Irak degraders and uses thereof

ABSTRACT

The present invention relates to heterobifunctional compounds (degraders), compositions and methods for treating diseases or conditions mediated by Interleukin Receptor-Associated Kinases (IRAKs).

RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62/630,538, filed Feb. 14, 2018, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Lymphoma is the most common blood cancer. Lymphoma occurs when lymphocytes multiply uncontrollably. The body has two main types of lymphocytes that can develop into lymphomas: B-lymphocytes (B-cells) and T-lymphocytes (T-cells).

Waldenstrom's macroglobulinemia (also known as lymphoplasmacytic lymphoma or immunocytoma) is a rare, indolent (slow-growing) B-cell lymphoma that occurs in less than two percent of patients with non-Hodgkin lymphoma. There are about 1,500 new cases of Waldenstrom's macroglobulinemia each year. The disease is primarily found in the bone marrow, although lymph nodes and the spleen may be involved.

The disease, named after the Swedish oncologist Jan G. Waldenstrom, was first identified in 1944. The proliferation of B-cells interferes with the production of red blood cells, resulting in anemia. A characteristic of the disease is that the B-cells produce excess amounts of the immunoglobulin IgM. These high levels of IgM can cause a thickening of the blood (hyper-viscosity) resulting in symptoms such as nosebleeds, headaches, dizziness, and blurring or loss of vision. Other symptoms may include tiredness, night sweats, headaches, pain or numbness in the extremities, and increased size of the liver, spleen, and lymph nodes.

There is a 2- to 3-fold risk increase of developing Waldenstrom's macroglobulinemia in people with a personal history of autoimmune diseases with autoantibodies and particularly elevated risks associated with hepatitis, human immunodeficiency virus, and rickettsiosis (Arch. Intern. Med. 168(17): 1903-9 (2008)).

Current treatment of Waldenstrom's macroglobulinemia (WM) includes the monoclonal antibody rituximab, sometimes in combination with chemotherapeutic drugs such as chlorambucil, cyclophosphamide, or vincristine or with thalidomide. Corticosteroids, such as Prednisone, may also be used in combination. Plasmapheresis can be used to treat the hyper-viscosity syndrome by removing the paraprotein from the blood, but this treatment does not address the underlying disease. Recently, autologous bone marrow transplantation has been added to the available treatment options. However, prior to the invention described herein, there was no single accepted treatment for Waldenstrom's macroglobulinemia. There can also be a marked variation in clinical outcomes. Objective response rates are high (>80%), but complete response rates are low (0-15%).

Thus, there is a need for effective treatment of WM.

SUMMARY OF THE INVENTION

A first aspect of the present invention is directed to a bifunctional compound having a structure represented by formula I:

wherein the targeting ligand represents a moiety that binds Interleukin-1 receptor kinase 1 (IRAK1), interleukin-1 receptor kinase 4 (IRAK4) or both IRAK1 and IRAK4 (IRAK1/4), the degron represents a moiety that binds an E3 ubiquitin ligase, and the linker represents a moiety that covalently connects the degron and the targeting ligand, or a pharmaceutically acceptable salt or stereoisomer thereof.

In another aspect, pharmaceutical composition including a therapeutically effective amount of the bifunctional compounds of the present invention, or a pharmaceutically acceptable salt or stereoisomer thereof, and a pharmaceutically acceptable carrier are provided.

In another aspect, methods of making the bifunctional compounds of the present invention are provided.

IRAK 1 and IRAK 4 are immune modulators that are involved in the etiology of a variety and multitude of diseases and disorders, both cancerous and non-cancerous alike. They are collectively referred to herein as “IRAK-mediated diseases and disorders.”

In a further aspect, methods of treating IRAK-mediated diseases or disorders are provided, which include administering a therapeutically effective amount of the compound to a subject in need thereof.

In some embodiments, the subject has cancer. In some embodiments, the cancer is a B-cell cancer. Exemplary B-cell cancers include Waldenstrom's macroglobulinemia (WM), activated B-cell ABC) diffuse large B-cell lymphoma (DLBCL), Primary CNS Lymphoma (PCNSL), Marginal Zone Lymphoma (MZL) and Chronic Lymphocytic Leukemia (CLL).

In some cases, the method further includes co-administering an inhibitor of Bruton's tyrosine kinase (BTK). An exemplary BTK inhibitor is ibrutinib.

In yet a further aspect, methods of degrading IRAK1, IRAK4 or both IRAK1 and 4 are provided, which include contacting a cell containing IRAK1, IRAK4 or both IRAK1 and 4 with an effective amount of the compounds or compositions of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-FIG. 1D area series of graphs indicating cellular viability IC₅₀ values for various WM (Waldenstrom's macroglobulinemia) cells and DLBCL (diffuse large B-cell lymphoma) cells after treatment with the degrader compounds of the present invention.

FIG. 1A is a graph of IC₅₀ curves for various WM and DLBCL cells after treatment with compound (CPD) 1.

FIG. 1B is a graph of IC₅₀ curves for various WM and DLBCL cells after treatment with CPD 2.

FIG. 1C is a graph of IC₅₀ curves for various WM and DLBCL cells after treatment with CPD 3.

FIG. 1D is a graph of IC₅₀ curves for various WM and DLBCL cells after treatment with CPD 4.

FIG. 2A-FIG. 2D are a series of graphs indicating cellular viability IC₅₀ values for various WM and DLBCL cells after treatment with degrader compound CPD 1 of the present invention, the IRAK1/4 inhibitor, CPD TL1, and the negative control, CPD C1.

FIG. 2A is a graph of IC₅₀ curves for various WM and DLBCL cells after treatment with CPD 1.

FIG. 2B is a graph of IC₅₀ curves for various WM and DLBCL cells after treatment with CPD TL1.

FIG. 2C is a graph of IC₅₀ curves for various WM and DLBCL cells after treatment with CPD 1.

FIG. 2D is a graph of IC₅₀ curves for various WM and DLBCL cells after treatment with CPD C1.

FIG. 3A and FIG. 3B are plots of intracellular IRAK1 (FIG. 3A) and IRAK4 (FIG. 3B) levels following IRAK1/4 degrader treatments in BCWM.1 cells (a Waldenstrom's macroglobulinemia cell line).

FIG. 4 is a Western blot showing the degradation of IRAK1 and IRAK4 proteins after treatment with different concentrations of inventive CPD 1, IRAK1/4 inhibitor TL1, and CPD C1 (negative control).

DETAILED DESCRIPTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in art to which the subject matter herein belongs. As used in the specification and the appended claims, unless specified to the contrary, the following terms have the meaning indicated in order to facilitate the understanding of the present invention.

As used in the description and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a composition” includes mixtures of two or more such compositions, reference to “an inhibitor” includes mixtures of two or more such inhibitors, and the like.

Unless stated otherwise, the term “about” means within 10% (e.g., within 5%, 2% or 1%) of the particular value modified by the term “about.”

The transitional term “comprising,” which is synonymous with “including,” “containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. By contrast, the transitional phrase “consisting of” excludes any element, step, or ingredient not specified in the claim. The transitional phrase “consisting essentially of” limits the scope of a claim to the specified materials or steps “and those that do not materially affect the basic and novel characteristic(s)” of the claimed invention.

With respect to compounds of the present invention, and to the extent the following terms are used herein to further describe them, the following definitions apply.

As used herein, the term “aliphatic” refers to a non-cyclic hydrocarbon group and includes branched and unbranched, alkyl, alkenyl, or alkynyl groups.

As used herein, the term “alkyl” refers to a saturated linear or branched-chain monovalent hydrocarbon radical. In one embodiment, the alkyl radical is a C₁-C₁₈ group. In other embodiments, the alkyl radical is a C₀-C₆, C₀-C₅, C₀-C₃, C₁-C₁₂, C₁-C₈, C₁-C₆, C₁-C₅, C₁-C₄ or C₁-C₃ group (wherein C₀ alkyl refers to a bond). Examples of alkyl groups include methyl, ethyl, 1-propyl, 2-propyl, i-propyl, 1-butyl, 2-methyl-1-propyl, 2-butyl, 2-methyl-2-propyl, 1-pentyl, n-pentyl, 2-pentyl, 3-pentyl, 2-methyl-2-butyl, 3-methyl-2-butyl, 3-methyl-1-butyl, 2-methyl-1-butyl, 1-hexyl, 2-hexyl, 3-hexyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 3-methyl-3-pentyl, 2-methyl-3-pentyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl. In some embodiments, an alkyl group is a C₁-C₃ alkyl group. In some embodiments, an alkyl group is a C₁-C₂ alkyl group.

As used herein, the term “alkylene” refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing no unsaturation and having from one to 12 carbon atoms, for example, methylene, ethylene, propylene, n-butylene, and the like. The alkylene chain may be attached to the rest of the molecule through a single bond and to the radical group through a single bond. In some embodiments, the alkylene group contains one to 8 carbon atoms (C₁-C₈ alkylene). In other embodiments, an alkylene group contains one to 5 carbon atoms (C₁-C₅ alkylene). In other embodiments, an alkylene group contains one to 4 carbon atoms (C₁-C₄ alkylene). In other embodiments, an alkylene contains one to three carbon atoms (C₁-C₃ alkylene). In other embodiments, an alkylene group contains one to two carbon atoms (C₁-C₂ alkylene). In other embodiments, an alkylene group contains one carbon atom (C₁ alkylene).

As used herein, the term “haloalkyl” refers to an alkyl group as defined herein that is substituted with one or more (e.g., 1, 2, 3, or 4) halo groups.

As used herein, the term “alkenyl” refers to a linear or branched-chain monovalent hydrocarbon radical with at least one carbon-carbon double bond. An alkenyl includes radicals having “cis” and “trans” orientations, or alternatively, “E” and “Z” orientations. In one example, the alkenyl radical is a C₂-C₁₈ group. In other embodiments, the alkenyl radical is a C₂-C₁₂, C₂-C₁₀, C₂-C₈, C₂-C₆ or C₂-C₃ group. Examples include ethenyl or vinyl, prop-1-enyl, prop-2-enyl, 2-methylprop-1-enyl, but-1-enyl, but-2-enyl, but-3-enyl, buta-1,3-dienyl, 2-methylbuta-1,3-diene, hex-1-enyl, hex-2-enyl, hex-3-enyl, hex-4-enyl and hexa-1,3-dienyl.

As used herein, the term “alkynyl” refers to a linear or branched monovalent hydrocarbon radical with at least one carbon-carbon triple bond. In one example, the alkynyl radical is a C₂-C₁₈ group. In other examples, the alkynyl radical is C₂-C₁₂, C₂-C₁₀, C₂-C₈, C₂-C₆ or C₂-C₃. Examples include ethynyl prop-1-ynyl, prop-2-ynyl, but-1-ynyl, but-2-ynyl and but-3-ynyl.

As used herein, the term “aldehyde” is represented by the formula —C(O)H. The terms “C(O)” and C═O are used interchangeably herein.

The terms “alkoxyl” or “alkoxy” as used herein refer to an alkyl group, as defined above, having an oxygen radical attached thereto. Representative alkoxyl groups include methoxy, ethoxy, propyloxy, tert-butoxy and the like. An “ether” is two hydrocarbons covalently linked by an oxygen. Accordingly, the substituent of an alkyl that renders that alkyl an ether is or resembles an alkoxyl, such as can be represented by one of —O-alkyl, —O-alkenyl, and —O-alkynyl.

As used herein, the term “halogen” (or “halo” or “halide”) refers to fluorine, chlorine, bromine, or iodine.

As used herein, the term “carboxylic acid” is represented by the formula-C(O)OH, and a “carboxylate” is represented by the formula —C(O)O—.

As used herein, the term “ester” is represented by the formula-OC(O)Z¹ or—C(O)OZ¹, where Z¹ may be an alkyl, halogenated alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group, all as described herein.

As used herein, the term “ether” is represented by the formula Z¹OZ², where Z¹ and Z² can be, independently, an alkyl, halogenated alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group, all as described herein.

As used herein, the term “ketone” is represented by the formula Z¹C(O)Z², where A¹ and A² independently represent alkyl, halogenated alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group, all as described herein.

As used herein, the term “sulfonyl” refers to the sulfo-oxo group represented by the formula —S(O)₂Z¹, where Z¹ may be hydrogen, an alkyl, halogenated alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group, all as described herein.

As used herein, the term “sulfonylamino” (or “sulfonamide”) is represented by the formula —S(O)₂NH₂.

As used herein, the term “thiol” is represented by the formula —SH.

As used herein, the term “cyclic group” broadly refers to any group that used alone or as part of a larger moiety, contains a saturated, partially saturated or aromatic ring system e.g., carbocyclic (cycloalkyl, cycloalkenyl), heterocyclic (heterocycloalkyl, heterocycloalkenyl), aryl and heteroaryl groups. Cyclic groups may have one or more (e.g., fused) ring systems. Thus, for example, a cyclic group can contain one or more carbocyclic, heterocyclic, aryl or heteroaryl groups.

As used herein, the term “carbocyclic” (also “carbocyclyl”) refers to a group that used alone or as part of a larger moiety, contains a saturated, partially unsaturated, or aromatic ring system having 3 to 20 carbon atoms, that is alone or part of a larger moiety (e.g., an alkcarbocyclic group). The term carbocyclyl includes mono-, bi-, tri-, fused, bridged, and spiro-ring systems, and combinations thereof. In one embodiment, carbocyclyl includes 3 to 15 carbon atoms (C₃-C₁₅). In one embodiment, carbocyclyl includes 3 to 12 carbon atoms (C₃-C₁₂). In another embodiment, carbocyclyl includes C₃-C₈, C₃-C₁₀ or C₅-C₁₀. In another embodiment, carbocyclyl, as a monocycle, includes C₃-C₈, C₃-C₆ or C₅-C₆. In some embodiments, carbocyclyl, as a bicycle, includes C₇-C₁₂. In another embodiment, carbocyclyl, as a spiro system, includes C₅-C₁₂.

Representative examples of monocyclic carbocyclyls include cyclopropyl, cyclobutyl, cyclopentyl, 1-cyclopent-1-enyl, 1-cyclopent-2-enyl, 1-cyclopent-3-enyl, cyclohexyl, perdeuteriocyclohexyl, 1-cyclohex-1-enyl, 1-cyclohex-2-enyl, 1-cyclohex-3-enyl, cyclohexadienyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, phenyl, and cyclododecyl, bicyclic carbocyclyls having 7 to 12 ring atoms include [4,3], [4,4], [4,5], [5,5], [5,6] or [6,6] ring systems, such as for example bicyclo[2.2.1]heptane, bicyclo[2.2.2]octane, naphthalene, and bicyclo[3.2.2]nonane. Representative examples of spiro carbocyclyls include spiro[2.2]pentane, spiro[2.3]hexane, spiro[2.4]heptane, spiro[2.5]octane and spiro[4.5]decane. The term carbocyclyl includes aryl ring systems as defined herein. The term carbocycyl also includes cycloalkyl rings (e.g., saturated or partially unsaturated mono-, bi-, or spiro-carbocycles). The term carbocyclic group also includes a carbocyclic ring fused to one or more (e.g., 1, 2 or 3) different cyclic groups (e.g., aryl or heterocyclic rings), where the radical or point of attachment is on the carbocyclic ring.

Thus, the term carbocyclic also embraces carbocyclylalkyl groups which as used herein refer to a group of the formula —R^(c)-carbocyclyl where R^(c) is an alkylene chain. The term carbocyclic also embraces carbocyclylalkoxy groups which as used herein refer to a group bonded through an oxygen atom of the formula —O—R^(c)-carbocyclyl where R^(c) is an alkylene chain.

As used herein, the term “heterocyclyl” refers to a “carbocyclyl” that used alone or as part of a larger moiety, contains a saturated, partially unsaturated or aromatic ring system, wherein one or more (e.g., 1, 2, 3, or 4) carbon atoms have been replaced with a heteroatom (e.g., O, N, N(O), S, S(O), or S(O)₂). The term heterocyclyl includes mono-, bi-, tri-, fused, bridged, and spiro-ring systems, and combinations thereof. In some embodiments, a heterocyclyl refers to a 3 to 15 membered heterocyclyl ring system. In some embodiments, a heterocyclyl refers to a 3 to 12 membered heterocyclyl ring system. In some embodiments, a heterocyclyl refers to a saturated ring system, such as a 3 to 12 membered saturated heterocyclyl ring system. In some embodiments, a heterocyclyl refers to a heteroaryl ring system, such as a 5 to 14 membered heteroaryl ring system. The term heterocyclyl also includes C₃-C₈ heterocycloalkyl, which is a saturated or partially unsaturated mono-, bi-, or spiro-ring system containing 3-8 carbons and one or more (1, 2, 3 or 4) heteroatoms.

In some embodiments, a heterocyclyl group includes 3-12 ring atoms and includes monocycles, bicycles, tricycles and Spiro ring systems, wherein the ring atoms are carbon, and one to 5 ring atoms is a heteroatom such as nitrogen, sulfur or oxygen. In some embodiments, heterocyclyl includes 3- to 7-membered monocycles having one or more heteroatoms selected from nitrogen, sulfur or oxygen. In some embodiments, heterocyclyl includes 4- to 6-membered monocycles having one or more heteroatoms selected from nitrogen, sulfur or oxygen. In some embodiments, heterocyclyl includes 3-membered monocycles. In some embodiments, heterocyclyl includes 4-membered monocycles. In some embodiments, heterocyclyl includes 5-6 membered monocycles. In some embodiments, the heterocyclyl group includes 0 to 3 double bonds. In any of the foregoing embodiments, heterocyclyl includes 1, 2, 3 or 4 heteroatoms. Any nitrogen or sulfur heteroatom may optionally be oxidized (e.g., NO, SO, SO₂), and any nitrogen heteroatom may optionally be quaternized (e.g., [NR₄]⁺Cl⁻, [NR₄]⁺OH⁻). Representative examples of heterocyclyls include oxiranyl, aziridinyl, thiiranyl, azetidinyl, oxetanyl, thietanyl, 1,2-dithietanyl, 1,3-dithietanyl, pyrrolidinyl, dihydro-1H-pyrrolyl, dihydrofuranyl, tetrahydropyranyl, dihydrothienyl, tetrahydrothienyl, imidazolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, 1,1-dioxo-thiomorpholinyl, dihydropyranyl, tetrahydropyranyl, hexahydrothiopyranyl, hexahydropyrimidinyl, oxazinanyl, thiazinanyl, thioxanyl, homopiperazinyl, homopiperidinyl, azepanyl, oxepanyl, thiepanyl, oxazepinyl, oxazepanyl, diazepanyl, 1,4-diazepanyl, diazepinyl, thiazepinyl, thiazepanyl, tetrahydrothiopyranyl, oxazolidinyl, thiazolidinyl, isothiazolidinyl, 1,1-dioxoisothiazolidinonyl, oxazolidinonyl, imidazolidinonyl, 4,5,6,7-tetrahydro[2H]indazolyl, tetrahydrobenzoimidazolyl, 4,5,6,7-tetrahydrobenzo[d]imidazolyl, 1,6-dihydroimidazol[4,5-d]pyrrolo[2,3-b]pyridinyl, thiazinyl, thiophenyl, oxazinyl, thiadiazinyl, oxadiazinyl, dithiazinyl, dioxazinyl, oxathiazinyl, thiatriazinyl, oxatriazinyl, dithiadiazinyl, imidazolinyl, dihydropyrimidyl, tetrahydropyrimidyl, 1-pyrrolinyl, 2-pyrrolinyl, 3-pyrrolinyl, indolinyl, thiapyranyl, 2H-pyranyl, 4H-pyranyl, dioxanyl, 1,3-dioxolanyl, pyrazolinyl, pyrazolidinyl, dithianyl, dithiolanyl, pyrimidinonyl, pyrimidindionyl, pyrimidin-2,4-dionyl, piperazinonyl, piperazindionyl, pyrazolidinylimidazolinyl, 3-azabicyclo[3.1.0]hexanyl, 3,6-diazabicyclo[3.1.1]heptanyl, 6-azabicyclo[3.1.1]heptanyl, 3-azabicyclo[3.1.1]heptanyl, 3-azabicyclo[4.1.0]heptanyl, azabicyclo[2.2.2]hexanyl, 2-azabicyclo[3.2.1]octanyl, 8-azabicyclo[3.2.1]octanyl, 2-azabicyclo[2.2.2]octanyl, 8-azabicyclo[2.2.2]octanyl, 7-oxabicyclo[2.2.1]heptane, azaspiro[3.5]nonanyl, azaspiro[2.5]octanyl, azaspiro[4.5]decanyl, 1-azaspiro[4.5]decan-2-only, azaspiro[5.5]undecanyl, tetrahydroindolyl, octahydroindolyl, tetrahydroisoindolyl, tetrahydroindazolyl, 1,1-dioxohexahydrothiopyranyl. Examples of 5-membered heterocyclyls containing a sulfur or oxygen atom and one to three nitrogen atoms are thiazolyl, including thiazol-2-yl and thiazol-2-yl N-oxide, thiadiazolyl, including 1,3,4-thiadiazol-5-yl and 1,2,4-thiadiazol-5-yl, oxazolyl, for example oxazol-2-yl, and oxadiazolyl, such as 1,3,4-oxadiazol-5-yl, and 1,2,4-oxadiazol-5-yl. Example 5-membered ring heterocyclyls containing 2 to 4 nitrogen atoms include imidazolyl, such as imidazol-2-yl; triazolyl, such as 1,3,4-triazol-5-yl; 1,2,3-triazol-5-yl, 1,2,4-triazol-5-yl, and tetrazolyl, such as 1H-tetrazol-5-yl. Representative examples of benzo-fused 5-membered heterocyclyls are benzoxazol-2-yl, benzthiazol-2-yl and benzimidazol-2-yl. Example 6-membered heterocyclyls contain one to three nitrogen atoms and optionally a sulfur or oxygen atom, for example pyridyl, such as pyrid-2-yl, pyrid-3-yl, and pyrid-4-yl; pyrimidyl, such as pyrimid-2-yl and pyrimid-4-yl; triazinyl, such as 1,3,4-triazin-2-yl and 1,3,5-triazin-4-yl; pyridazinyl, in particular pyridazin-3-yl, and pyrazinyl. The pyridine N-oxides and pyridazine N-oxides and the pyridyl, pyrimid-2-yl, pyrimid-4-yl, pyridazinyl and the 1,3,4-triazin-2-yl groups, are yet other examples of heterocyclyl groups. In some embodiments, a heterocyclic group includes a heterocyclic ring fused to one or more (e.g., 1, 2 or 3) different cyclic groups (e.g., carbocyclic rings or heterocyclic rings), where the radical or point of attachment is on the heterocyclic ring, and in some embodiments wherein the point of attachment is a heteroatom contained in the heterocyclic ring.

Thus, the term heterocyclic embraces N-heterocyclyl groups which as used herein refer to a heterocyclyl group containing at least one nitrogen and where the point of attachment of the heterocyclyl group to the rest of the molecule is through a nitrogen atom in the heterocyclyl group. Representative examples of N-heterocyclyl groups include 1-morpholinyl, 1-piperidinyl, 1-piperazinyl, 1-pyrrolidinyl, pyrazolidinyl, imidazolinyl and imidazolidinyl. The term heterocyclic also embraces C-heterocyclyl groups which as used herein refer to a heterocyclyl group containing at least one heteroatom and where the point of attachment of the heterocyclyl group to the rest of the molecule is through a carbon atom in the heterocyclyl group. Representative examples of C-heterocyclyl radicals include 2-morpholinyl, 2- or 3- or 4-piperidinyl, 2-piperazinyl, and 2- or 3-pyrrolidinyl. The term heterocyclic also embraces heterocyclylalkyl groups which as disclosed above refer to a group of the formula —R^(c)-heterocyclyl where R^(c) is an alkylene chain. The term heterocyclic also embraces heterocyclylalkoxy groups which as used herein refer to a radical bonded through an oxygen atom of the formula —O—R^(c)-heterocyclyl where R^(c) is an alkylene chain.

As used herein, the term “aryl” used alone or as part of a larger moiety (e.g., “aralkyl”, wherein the terminal carbon atom on the alkyl group is the point of attachment, e.g., a benzyl group), “aralkoxy” wherein the oxygen atom is the point of attachment, or “aroxyalkyl” wherein the point of attachment is on the aryl group) refers to a group that includes monocyclic, bicyclic or tricyclic, carbon ring system, that includes fused rings, wherein at least one ring in the system is aromatic. In some embodiments, the aralkoxy group is a benzoxy group. The term “aryl” may be used interchangeably with the term “aryl ring”. In one embodiment, aryl includes groups having 6-18 carbon atoms. In another embodiment, aryl includes groups having 6-10 carbon atoms. Examples of aryl groups include phenyl, naphthyl, anthracyl, biphenyl, phenanthrenyl, naphthacenyl, 1,2,3,4-tetrahydronaphthalenyl, 1H-indenyl, 2,3-dihydro-1H-indenyl, naphthyridinyl, and the like, which may be substituted or independently substituted by one or more substituents described herein. A particular aryl is phenyl. In some embodiments, an aryl group includes an aryl ring fused to one or more (e.g., 1, 2 or 3) different cyclic groups (e.g., carbocyclic rings or heterocyclic rings), where the radical or point of attachment is on the aryl ring.

Thus, the term aryl embraces aralkyl groups (e.g., benzyl) which as disclosed above refer to a group of the formula —R^(c)-aryl where R^(c) is an alkylene chain such as methylene or ethylene. In some embodiments, the aralkyl group is an optionally substituted benzyl group. The term aryl also embraces aralkoxy groups which as used herein refer to a group bonded through an oxygen atom of the formula —O—R^(c)-aryl where R^(c) is an alkylene chain such as methylene or ethylene.

As used herein, the term “heteroaryl” used alone or as part of a larger moiety (e.g., “heteroarylalkyl” (also “heteroaralkyl”), or “heteroarylalkoxy” (also “heteroaralkoxy”), refers to a monocyclic, bicyclic or tricyclic ring system having 5 to 14 ring atoms, wherein at least one ring is aromatic and contains at least one heteroatom. In one embodiment, heteroaryl includes 4-6 membered monocyclic aromatic groups where one or more ring atoms is nitrogen, sulfur or oxygen that is independently optionally substituted. In another embodiment, heteroaryl includes 5-6 membered monocyclic aromatic groups where one or more ring atoms is nitrogen, sulfur or oxygen. Representative examples of heteroaryl groups include thienyl, furyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, triazolyl, thiadiazolyl, oxadiazolyl, tetrazolyl, thiatriazolyl, oxatriazolyl, pyridyl, pyrimidyl, imidazopyridyl, pyrazinyl, pyridazinyl, triazinyl, tetrazinyl, tetrazolo[1,5-b]pyridazinyl, purinyl, deazapurinyl, benzoxazolyl, benzofuryl, benzothiazolyl, benzothiadiazolyl, benzotriazolyl, benzoimidazolyl, indolyl, 1,3-thiazol-2-yl, 1,3,4-triazol-5-yl, 1,3-oxazol-2-yl, 1,3,4-oxadiazol-5-yl, 1,2,4-oxadiazol-5-yl, 1,3,4-thiadiazol-5-yl, 1H-tetrazol-5-yl, 1,2,3-triazol-5-yl, and pyrid-2-yl N-oxide. The term “heteroaryl” also includes groups in which a heteroaryl is fused to one or more cyclic (e.g., carbocyclyl, or heterocyclyl) rings, where the radical or point of attachment is on the heteroaryl ring. Nonlimiting examples include indolyl, indolizinyl, isoindolyl, benzothienyl, benzothiophenyl, methylenedioxyphenyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzodioxazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl and pyrido[2,3-b]-1,4-oxazin-3(4H)-one. A heteroaryl group may be mono-, bi- or tri-cyclic. In some embodiments, a heteroaryl group includes a heteroaryl ring fused to one or more (e.g., 1, 2 or 3) different cyclic groups (e.g., carbocyclic rings or heterocyclic rings), where the radical or point of attachment is on the heteroaryl ring, and in some embodiments wherein the point of attachment is a heteroatom contained in the heterocyclic ring.

Thus, the term heteroaryl embraces N-heteroaryl groups which as used herein refer to a heteroaryl group as defined above containing at least one nitrogen and where the point of attachment of the heteroaryl group to the rest of the molecule is through a nitrogen atom in the heteroaryl group. The term heteroaryl also embraces C-heteroaryl groups which as used herein refer to a heteroaryl group as defined above and where the point of attachment of the heteroaryl group to the rest of the molecule is through a carbon atom in the heteroaryl group. The term heteroaryl also embraces heteroarylalkyl groups which as disclosed above refer to a group of the formula —R^(c)-heteroaryl, wherein R^(c) is an alkylene chain as defined above. The term heteroaryl also embraces heteroaralkoxy (or heteroarylalkoxy) groups which as used herein refer to a group bonded through an oxygen atom of the formula —O—R^(c)-heteroaryl, where R^(c) is an alkylene group as defined above.

Any of the groups described herein may be substituted or unsubstituted. As used herein, the term “substituted” broadly refers to all permissible substituents with the implicit proviso that such substitution is in accordance with permitted valence of the substituted atom and the substituent, and that the substitution results in a stable compound, i.e. a compound that does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, etc. Representative substituents include halogens, hydroxyl groups, and any other organic groupings containing any number of carbon atoms, e.g., 1-14 carbon atoms, and which may include one or more (e.g., 1 2 3, or 4) heteroatoms such as oxygen, sulfur, and nitrogen grouped in a linear, branched, or cyclic structural format.

Representative examples of substituents may thus include alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cyclic, substituted cyclic, carbocyclic, substituted carbocyclic, heterocyclic, substituted heterocyclic, aryl (e.g., benzyl and phenyl), substituted aryl (e.g., substituted phenyl), heteroaryl, substituted heteroaryl, or NR₆R₇, wherein each of R₆ and R₇ independently represents H, optionally substituted aryl or optionally substituted aralkyl, halo, hydroxyl, alkoxy, substituted alkoxy, aryloxy, substituted aryloxy, alkylthio, substituted alkylthio, arylthio, substituted arylthio, cyano, isocyano, substituted isocyano, carbonyl, substituted carbonyl, carboxyl, substituted carboxyl, amino, substituted amino, amido, substituted amido, sulfonyl, substituted sulfonyl, sulfonic acid, phosphoryl, substituted phosphoryl, phosphonyl, substituted phosphonyl, amino acid, peptide, and polypeptide groups.

The term “binding” as it relates to interaction between the targeting ligand and the targeted protein or proteins, which in this invention are Interleukin-1 receptor kinase 1 (IRAK1), interleukin-1 receptor kinase 4 (IRAK4) or both IRAK1 and IRAK4 (IRAK1/4), typically refers to an inter-molecular interaction that may be preferential or substantially specific in that binding of the targeting ligand with other proteinaceous entities present in the cell is functionally insignificant. The present bifunctional compounds may preferentially bind and recruit IRAK1, IRAK4 or both IRAK1 and IRAK4 (IRAK1/4) for targeted degradation.

The term “binding” as it relates to interaction between the degron and the E3 ubiquitin ligase, typically refers to an inter-molecular interaction that may or may not exhibit an affinity level that equals or exceeds that affinity between the targeting ligand and the target protein, but nonetheless wherein the affinity is sufficient to achieve recruitment of the ligase to the targeted degradation and the selective degradation of the targeted protein.

Broadly, the bifunctional compounds of the present invention have a structure represented by formula I:

wherein the targeting ligand represents a moiety that binds Interleukin-1 receptor kinase 1 (IRAK1), interleukin-1 receptor kinase 4 (IRAK4) or both IRAK1 and IRAK4 (IRAK1/4), the degron represents a moiety that binds an E3 ubiquitin ligase, and the linker represents a moiety that covalently connects the degron and the targeting ligand, or a pharmaceutically acceptable salt or stereoisomer thereof.

Targeting Ligand

Interleukin-1 receptor-associated kinases are a family of intracellular serine-threonine kinases, which consists of IRAK1, IRAK2, IRAK3 (also known as IRAKM), and IRAK4. See, Li, et al., Proc. Nat'l. Acad. Sci. USA, 99:5567-72 (2002). IRAK4 signals downstream of the pathogen sensing toll-like receptors (TLRs), except for TLR3, and the innate/adaptive immune signaling IL-1 family (the IL-1, IL-18, and IL-33 receptors). See, Chaudhary, et al., J. Med. Chem. 58:96-110 (2015). Upon binding to the IL-1 receptors or the TLRs, these receptors recruit the adaptor protein myeloid differentiation primary response gene 88 (MyD88) through the conserved Toll-IL-R (TIR) domain. MyD88 then utilizes the death domain (DD) homotypic interaction to recruit IRAK4 (Lin, et al., Nature 465:885-90 (2010)). IRAK4 activation leads to the recruitment and phosphorylation of IRAK1 or IRAK2, which then leads to MAP kinaseIKK activation and pro-inflammatory cytokine production. Activation of TLR downstream targets like cytokines TNF and IL-1 can result in a systemic disorder like sepsis or local, autoimmune and chronic inflammation disease like rheumatoid arthritis or inflammatory bowel syndrome. IRAK4 activation has also been implicated in cancer. For example, activating MyD88 mutations such as L265P in activated diffuse large B-cell lymphoma (DLBCL) and Waldenstrom's macroglobulinemia (WM) have established a role for IRAK family signaling in these and other cancers (Rhyasen and Starczynowski, Brit. J. Cancer 112:232-37 (2015)).

The targeting ligand (TL), which is a functional modality of the present compounds, binds IRAK1, IRAK4 or both IRAK1 and 4 (“IRAK1/4”).

In some embodiments, the targeting ligand is an analog of IRAK1/4 inhibitor TL1:

In some embodiments, the TL1 analog has a structure represented by formula TL1-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-1:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of IRAK inhibitor TL2:

In some embodiments, the TL2 analog has a structure represented by formula TL2-a:

wherein R is H or methyl. Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-2:

wherein R is H or methyl, or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of compound T3:

In some embodiments, the TL3 analog has a structure represented by formula TL3-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-3a:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the TL3 analog has a structure represented by formula TL3-b:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-3b:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of compound TL4:

In some embodiments, the TL4 analog has a structure represented by formula TL4-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-4a:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the TL4 analog has a structure represented by formula TL4-b:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-4b:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of IRAK4 inhibitor AS2444697 (TL5):

In some embodiments, the AS2444697 analog has a structure represented by formula TL5-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-5a:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the AS2444697 analog has a structure represented by formula TL5-b:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-5b:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of IRAK1/4 inhibitor TL6:

In some embodiments, the TL6 analog has a structure represented by formula TL6-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-6a:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the TL6 analog has a structure represented by formula TL6-b:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-6b:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of compound PF06650833 (TL7):

In some embodiments, the PF06650833 analog has a structure represented by formula TL7-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-7a:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the PF06650833 analog has a structure represented by formula TL7-b:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-7b:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of compound TL8:

In some embodiments, the TL8 analog has a structure represented by formula TL8-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-8:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of compound TL9:

In some embodiments, the TL9 analog has a structure represented by formula TL9-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-9a:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the TL9 analog has a structure represented by formula TL9-b:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-9b:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of compound TL 10:

In some embodiments, the TL10 analog has a structure represented by formula TL10-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-10a:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the TL10 analog has a structure represented by formula TL10-b:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-10b:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the targeting ligand is an analog of compound TL11:

In some embodiments, the TL11 analog has a structure represented by formula TL11-a:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-11a:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the TL11 analog has a structure represented by formula TL11-b:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-11b:

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the TL11 analog has a structure represented by formula TL11-c:

Thus, in some embodiments, the compounds of the present invention have a structure represented by formula I-11c:

or a pharmaceutically acceptable salt or stereoisomer thereof.

Yet other representative examples of targeting ligands that may be used in the synthesis of the compounds of the present invention are known in the art. See, e.g., U.S. Pat. Nos. 9,732,095 and 9,598,440, and U.S. Patent Application Publication Nos 2017/0305901, 2017/0275297, 2017/0247388, 2017/0217981, 2017/0152263, 2017/0035881, 2016/0340366, 2016/0326151, 2016/0318878, 2016/0311807, 2016/0030443, 2016/0002265, 2015/0299224, 2015/0274708, and 2015/0191464.

Linkers

The Linker (“L”) provides a covalent attachment of the targeting ligand to the Degron. The structure of Linker may not be critical, provided it does not substantially interfere with the activity of the targeting ligand or the Degron. In some embodiments, the Linker is an alkylene linker (e.g., having 0-11, inclusive, alkylene units). In other embodiments, the Linker may be a bivalent alkylene linker interrupted by, or terminating in (at either or both termini at least one of —O—, —S—, —N(R′)—, —C(O)—, —C(O)O—, —OC(O)—, —OC(O)O—, —C(NOR′)—, —C(O)N(R′)—, —C(O)N(R′)C(O)—, —C(O)N(R′)C(O)N(R′)—, —N(R′)C(O)—, —N(R′)C(O)N(R′)—, —N(R′)C(O)O—, —OC(O)N(R′)—, —C(NR′)—, —N(R′)C(NR′)—, —C(NR′)N(R′)—, —N(R′)C(NR′)N(R′)—, —S(O)₂—, —OS(O)—, —S(O)O—, —S(O)—, —OS(O)₂—, —S(O)₂₀—, —N(R′)S(O)₂—, —S(O)₂N(R′)—, —N(R′)S(O)—, —S(O)N(R′)—, —N(R′)S(O)₂N(R′)—, —N(R′)S(O)N(R′)—, C₃₋₁₂ carbocyclene, 3- to 12-membered heterocyclene, 5- to 12-membered heteroarylene or any combination thereof, wherein R′ is H or C₁-C₆ alkyl. In some embodiments the linker may be C1-C10 alkylene terminating in NH-group wherein the nitrogen is also bound to the degron.

“Carbocyclene” refers to a bivalent carbocycle radical, which is optionally substituted.

“Heterocyclene” refers to a bivalent heterocyclyl radical which may be optionally substituted.

“Heteroarylene” refers to a bivalent heteroaryl radical which may be optionally substituted.

Representative examples of Linkers that may be suitable for use in the present invention include alkylene linkers:

wherein n is an integer of 1-10, inclusive, e.g., 1-9, 1-8, 1-7, 1-6, 1-5, 1-4, 1-3, 1-2, 2-10, 2-9, 2-8, 2-7, 2-6, 2-5, 2-4, 2-3, 3-10, 3-9, 3-8, 3-7, 3-6, 3-5, 3-4, 4-10, 4-9, 4-8, 4-7, 4-6, 4-5, 5-10, 5-9, 5-8, 5-7, 5-6, 6-10, 6-9, 6-8, 6-7, 7-10, 7-9, 7-8, 8-10, 8-9, 9-10 and 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 examples of which include:

alkylene linkers terminating in various functional groups (as described above), examples of which are as follows:

alkylene linkers interrupted by heterocyclene groups, e.g.,

wherein n is an integer of 1-10, inclusive, e.g., 1-9, 1-8, 1-7, 1-6, 1-5, 1-4, 1-3, 1-2, 2-10, 2-9, 2-8, 2-7, 2-6, 2-5, 2-4, 2-3, 3-10, 3-9, 3-8, 3-7, 3-6, 3-5, 3-4, 4-10, 4-9, 4-8, 4-7, 4-6, 4-5, 5-10, 5-9, 5-8, 5-7, 5-6, 6-10, 6-9, 6-8, 6-7, 7-10, 7-9, 7-8, 8-10, 8-9, 9-10 and 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 examples of which include:

alkylene linkers interrupted by both heterocyclene and aryl groups, examples of which include:

alkylene linkers interrupted by heterocyclene and aryl groups, and a heteroatom, examples of which include:

and alkylene linkers interrupted by a heteroatom, e.g.,

wherein n is an integer of 1-10, inclusive, e.g., 1-9, 1-8, 1-7, 1-6, 1-5, 1-4, 1-3, 1-2, 2-10, 2-9, 2-8, 2-7, 2-6, 2-5, 2-4, 2-3, 3-10, 3-9, 3-8, 3-7, 3-6, 3-5, 3-4, 4-10, 4-9, 4-8, 4-7, 4-6, 4-5, 5-10, 5-9, 5-8, 5-7, 5-6, 6-10, 6-9, 6-8, 6-7, 7-10, 7-9, 7-8, 8-10, 8-9, 9-10, and 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10, and R is C1 to C4 alkyl an example of which includes

In some embodiments, the linker is

wherein R_(L2) is NH or CO, m is 1, n is 2-4, R_(L1) is RaCO, Ra is C₂ alkyl or

Thus, in some embodiments, the compounds of the present invention are represented by structure I-12:

wherein R_(L2) is NH or CO, m is 1, n is 2-4, R_(L1) is RaCO, Ra is C₂ alkyl or

or a pharmaceutically acceptable salt or stereoisomer thereof.

In some embodiments, the linker is represented by a structure selected from the group consisting of:

Degron

The Ubiquitin-Proteasome Pathway (UPP) is a critical cellular pathway that regulates key regulator proteins and degrades misfolded or abnormal proteins. UPP is central to multiple cellular processes. If defective or imbalanced, it leads to pathogenesis of a variety of diseases. The covalent attachment of ubiquitin to specific protein substrates is achieved through the action of E3 ubiquitin ligases. These ligases include over 500 different proteins and are categorized into multiple classes defined by the structural element of their E3 functional activity.

The degron, which constitutes one functional modality of the present compounds, binds an E3 ubiquitin ligase. The ligase catalyzes the covalent attachment of ubiquitin to the target protein, which in turn induces degradation of the target protein by native proteasomes. Thus, the compounds of the present invention are designed in a manner that exploits native cellular degradative processes but wherein the degradative action is homed to unwanted target proteins that are involved in disease etiology.

In some embodiments, the degron binds cereblon. Representative degrons that bind cereblon may be represented by formula D1:

wherein Y is a bond, N, O, S, (CH₂)₁₋₆, (CH₂)₀₋₆—O, (CH₂)₀₋₆—C(O)NR_(2′), (CH₂)₀₋₆—NR_(2′)C(O), (CH₂)₀₋₆—NH, or (CH₂)₀₋₆—NR₂; X is C(O) or C(R₆)₂;

X′ is NH or CH₂;

each R₁ is independently halogen, OH, C₁-C₆ alkyl, or C₁-C₆ alkoxy; each R₃ is independently H or C₁-C₃ alkyl; each R₂ is independently H or C₁-C₃ alkyl; each R₄ is independently H or C₁-C₃ alkyl; or R₂ and R₄, together with the carbon atom to which they are attached, form C(O), a C₃-C₆ carbocycle, or a 4-, 5-, or 6-membered heterocycle including 1 or 2 heteroatoms selected from N and O; R₅ is H, deuterium, C₁-C₃ alkyl, F, or Cl; R₆ is H or C₁-C₃ alkyl; m is 0, 1, 2 or 3; and n is 0, 1 or 2.

Thus, in some embodiments, the compounds of this invention are represented by formula I-13:

or a pharmaceutically acceptable salt, isotopic derivative or stereoisomer thereof, wherein X, X′, Y, R₁, R₂, R₃, R₄, R₅, m and n are each as defined above, or a pharmaceutically acceptable salt or stereoisomer thereof.

In certain embodiments, the degron binds cereblon and is represented by a structure selected from the group consisting of:

Thus, in some embodiments, the compounds of this invention are represented by a formula selected from the group consisting of:

or a pharmaceutically acceptable salt, isotopic derivative or stereoisomer thereof.

Yet other degrons that bind cereblon and which may be suitable for use in the present invention are disclosed in U.S. Pat. No. 9,770,512, and U.S. Patent Application Publication Nos. 2018/0015087, 2018/0009779, 2016/0243247, 2016/0235731, 2016/0235730, and 2016/0176916, and International Patent Publications WO 2017/197055, WO 2017/197051, WO 2017/197036, WO 2017/197056 and WO 2017/197046.

In some embodiments, the E3 ubiquitin ligase that is bound by the degron is the von Hippel-Lindau (VHL) tumor suppressor. See, Iwai et al., Proc. Nat'l. Acad. Sci. USA 96:12436-41(1999).

Additional examples of the degrons that bind VHL are represented by the following formulae:

wherein Y′ is a bond, N, O or C;

wherein Z is a cyclic group.

In some embodiments, the present invention provides a compound represented by any of the following formulae:

wherein Y′ is a bond, N, O or C; or

wherein Z is a cyclic group; or a pharmaceutically acceptable salt, isotopic isomer or stereoisomer thereof.

Yet other degrons that bind VHL and which may be suitable for use in the present invention are disclosed in U.S. Patent Application Publication 2017/0121321 A1.

Thus, in some embodiments, the compounds of the present invention are represented by any structures generated by the combination of structures TL-1a to TL-11c, L1 to L7 and the structures of the degrons described herein, including D1 to D2-d, or a pharmaceutically acceptable salts or stereoisomers thereof.

In some embodiments, the present degrader compounds have the following structures:

and pharmaceutically acceptable salts and stereoisomers thereof.

Compounds 1-5 bind cereblon and IRAK/4; compound 6 binds VHL and IRAK1/4.

Compounds of the present invention may be in the form of a free acid or free base, or a pharmaceutically acceptable salt. As used herein, the term “pharmaceutically acceptable” refers to a material, such as a carrier or diluent, which does not abrogate the biological activity or properties of the compound, and is relatively non-toxic, i.e., the material may be administered to a subject without causing undesirable biological effects (such as dizziness or gastric upset) or interacting in a deleterious manner with any of the components of the composition in which it is contained. The term “pharmaceutically acceptable salt” refers to a product obtained by reaction of the compound of the present invention with a suitable acid or a base. Examples of pharmaceutically acceptable salts of the compounds of this invention include those derived from suitable inorganic bases such as Li, Na, K, Ca, Mg, Fe, Cu, Al, Zn and Mn salts. Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, isonicotinate, acetate, lactate, salicylate, citrate, tartrate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucaronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, 4-methylbenzenesulfonate or p-toluenesulfonate salts and the like. Certain compounds of the invention can form pharmaceutically acceptable salts with various organic bases such as lysine, arginine, guanidine, diethanolamine or metformin.

In some embodiments, the compound of the present invention is an isotopic derivative in that it has at least one desired isotopic substitution of an atom, at an amount above the natural abundance of the isotope, i.e., enriched. In one embodiment, the compound includes deuterium or multiple deuterium atoms. Substitution with heavier isotopes such as deuterium, i.e. ²H, may afford certain therapeutic advantages resulting from greater metabolic stability, for example, increased in vivo half-life or reduced dosage requirements, and thus may be advantageous in some circumstances.

Compounds of the present invention may have at least one chiral center and thus may be in the form of a stereoisomer, which as used herein, embraces all isomers of individual compounds that differ only in the orientation of their atoms in space. The term stereoisomer includes mirror image isomers (enantiomers which include the (R-) or (S-) configurations of the compounds), mixtures of mirror image isomers (physical mixtures of the enantiomers, and racemates or racemic mixtures) of compounds, geometric (cis/trans or E/Z, R/S) isomers of compounds and isomers of compounds with more than one chiral center that are not mirror images of one another (diastereoisomers). The chiral centers of the compounds may undergo epimerization in vivo; thus, for these compounds, administration of the compound in its (R-) form is considered equivalent to administration of the compound in its (S-) form. Accordingly, the compounds of the present invention may be made and used in the form of individual isomers and substantially free of other isomers, or in the form of a mixture of various isomers, e.g., racemic mixtures of stereoisomers.

Methods of Synthesis

In another aspect, the present invention is directed to a method for making a bispecific compound of formula I, or a pharmaceutically acceptable salt or stereoisomer thereof. Broadly, the inventive compounds or pharmaceutically-acceptable salts or stereoisomers thereof may be prepared by any process known to be applicable to the preparation of chemically related compounds. The compounds of the present invention will be better understood in connection with the synthetic schemes that described in various working examples and which illustrate nonlimiting methods by which the compounds of the invention may be prepared.

Pharmaceutical Compositions

In some embodiments, the present invention is directed to a pharmaceutical composition that includes a therapeutically effective amount of the bispecific compound of formula I or a pharmaceutically acceptable salt or stereoisomer thereof, and a pharmaceutically acceptable carrier. The compounds of the present invention may be formulated into several different types of pharmaceutical compositions that contain a therapeutically effective amount of the compound, and a pharmaceutically acceptable carrier.

Broadly, the inventive compounds may be formulated into a given type of composition in accordance with conventional pharmaceutical practice such as conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping and compression processes (see, e.g., Remington: The Science and Practice of Pharmacy (20th ed.), ed. A. R. Gennaro, Lippincott Williams & Wilkins, 2000 and Encyclopedia of Pharmaceutical Technology, eds. J. Swarbrick and J. C. Boylan, 1988-1999, Marcel Dekker, New York). The type of formulation depends on the mode of administration which may include enteral (e.g., oral), parenteral (e.g., subcutaneous (s.c.), intravenous (i.v.), intramuscular (i.m.), and intrasternal injection, or infusion techniques, intra-arterial, intramedullary, intrathecal, intraventricular, transdermal, interdermal, rectal, intravaginal, intraperitoneal, topical mucosal, nasal, buccal, sublingual, intratracheal instillation, bronchial instillation, and/or inhalation. In general, the most appropriate route of administration will depend upon a variety of factors including, for example, the nature of the agent (e.g., its stability in the environment of the gastrointestinal tract), and/or the condition of the subject (e.g., whether the subject is able to tolerate oral administration). In some embodiments, the compositions are formulated for oral or intravenous administration (e.g., systemic intravenous injection).

The term “pharmaceutically acceptable carrier,” as known in the art, refers to a pharmaceutically acceptable material, composition or vehicle, suitable for administering compounds of the present invention to mammals. Suitable carriers may include, for example, liquids (both aqueous and non-aqueous alike, and combinations thereof), solids, encapsulating materials, gases, and combinations thereof (e.g., semi-solids), that function to carry or transport the compound from one organ, or portion of the body, to another organ or portion of the body. A carrier is “acceptable” in the sense of being physiologically inert to and compatible with the other ingredients of the formulation, and which is non-toxic to the subject or patient. Depending on the type of formulation, the composition may further include one or more pharmaceutically acceptable excipients.

Accordingly, compounds of formula I may be formulated into solid compositions (e.g., powders, tablets, dispersible granules, capsules, cachets, and suppositories), liquid compositions (e.g., solutions in which the compound is dissolved, suspensions in which solid particles of the compound are dispersed, emulsions, and solutions containing liposomes, micelles, or nanoparticles, syrups and elixirs); semi-solid compositions (e.g., gels, suspensions and creams); and gases (e.g., propellants for aerosol compositions). Compounds may also be formulated for rapid, intermediate or extended release.

Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with a carrier such as sodium citrate or dicalcium phosphate and an additional carrier or excipient such as a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, methylcellulose, microcrystalline cellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as crosslinked polymers (e.g., crosslinked polyvinylpyrrolidone (crospovidone), crosslinked sodium carboxymethyl cellulose (croscarmellose sodium), sodium starch glycolate, agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also include buffering agents. Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings. They may further contain an opacifying agent.

In some embodiments, compounds of formula I of the present invention may be formulated in a hard or soft gelatin capsule. Representative excipients that may be used include pregelatinized starch, magnesium stearate, mannitol, sodium stearyl fumarate, lactose anhydrous, microcrystalline cellulose and croscarmellose sodium. Gelatin shells may include gelatin, titanium dioxide, iron oxides and colorants.

In some embodiments, compounds of formula I of the present invention may be formulated into tablets that may include excipients such as lactose monohydrate, microcrystalline cellulose, sodium starch glycolate, magnesium tartrate, and hydrophobic colloidal silica.

They may be formulated as solutions for parenteral and oral delivery forms, particularly to the extent that they are water-soluble. Parenteral administration may also be advantageous in that the compound may be administered relatively quickly such as in the case of a single-dose treatment and/or an acute condition.

Injectable preparations for parenteral administration may include sterile aqueous solutions or oleaginous suspensions. They may be formulated according to standard techniques using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, U.S.P. and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil can be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are used in the preparation of injectables. The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium prior to use. The effect of the compound may be prolonged by slowing its absorption, which may be accomplished by the use of a liquid suspension or crystalline or amorphous material with poor water solubility. Prolonged absorption of the compound from a parenterally administered formulation may also be accomplished by suspending the compound in an oily vehicle.

In certain embodiments, compounds of formula I of the present invention may be administered in a local rather than systemic manner, for example, via injection of the conjugate directly into an organ, often in a depot preparation or sustained release formulation. In specific embodiments, long acting formulations are administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection. Injectable depot forms are made by forming microencapsule matrices of the compound in a biodegradable polymer, e.g., polylactide-polyglycolides, poly(orthoesters) and poly(anhydrides). The rate of release of the compound may be controlled by varying the ratio of compound to polymer and the nature of the particular polymer employed. Depot injectable formulations are also prepared by entrapping the compound in liposomes or microemulsions that are compatible with body tissues. Furthermore, in other embodiments, the compound is delivered in a targeted drug delivery system, for example, in a liposome coated with organ-specific antibody. In such embodiments, the liposomes are targeted to and taken up selectively by the organ.

Liquid dosage forms for oral administration include solutions, suspensions, emulsions, micro-emulsions, syrups and elixirs. In addition to the compound, the liquid dosage forms may contain an aqueous or non-aqueous carrier (depending upon the solubility of the compounds) commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethylformamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Oral compositions may also include an excipients such as wetting agents, suspending agents, coloring, sweetening, flavoring, and perfuming agents.

The compositions may be formulated for buccal or sublingual administration, examples of which include tablets, lozenges and gels.

The compositions formula I may be formulated for administration by inhalation. Various forms suitable for administration by inhalation include aerosols, mists or powders. Pharmaceutical compositions may be delivered in the form of an aerosol spray presentation from pressurized packs or a nebulizer, with the use of a suitable propellant (e.g., dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas). In some embodiments, the dosage unit of a pressurized aerosol may be determined by providing a valve to deliver a metered amount. In some embodiments, capsules and cartridges including gelatin, for example, for use in an inhaler or insufflator, may be formulated containing a powder mix of the compound and a suitable powder base such as lactose or starch.

Compounds formula I may be formulated for topical administration which as used herein, refers to administration intradermally by invention of the formulation to the epidermis. These types of compositions are typically in the form of ointments, pastes, creams, lotions, gels, solutions and sprays.

Representative examples of carriers useful in formulating compositions for topical application include solvents (e.g., alcohols, poly alcohols, water), creams, lotions, ointments, oils, plasters, liposomes, powders, emulsions, microemulsions, and buffered solutions (e.g., hypotonic or buffered saline). Creams, for example, may be formulated using saturated or unsaturated fatty acids such as stearic acid, palmitic acid, oleic acid, palmito-oleic acid, cetyl, or oleyl alcohols. Creams may also contain a non-ionic surfactant such as polyoxy-40-stearate.

In some embodiments, the topical formulations may also include an excipient, an example of which is a penetration enhancing agent. These agents are capable of transporting a pharmacologically active compound through the stratum corneum and into the epidermis or dermis, preferably, with little or no systemic absorption. A wide variety of compounds have been evaluated as to their effectiveness in enhancing the rate of penetration of drugs through the skin. See, for example, Percutaneous Penetration Enhancers, Maibach H. I. and Smith H. E. (eds.), CRC Press, Inc., Boca Raton, Fla. (1995), which surveys the use and testing of various skin penetration enhancers, and Buyuktimkin et al., Chemical Means of Transdermal Drug Permeation Enhancement in Transdermal and Topical Drug Delivery Systems, Gosh T. K., Pfister W. R., Yum S. I. (Eds.), Interpharm Press Inc., Buffalo Grove, Ill. (1997). Representative examples of penetration enhancing agents include triglycerides (e.g., soybean oil), aloe compositions (e.g., aloe-vera gel), ethyl alcohol, isopropyl alcohol, octolyphenylpolyethylene glycol, oleic acid, polyethylene glycol 400, propylene glycol, N-decylmethylsulfoxide, fatty acid esters (e.g., isopropyl myristate, methyl laurate, glycerol monooleate, and propylene glycol monooleate), and N-methylpyrrolidone.

Representative examples of yet other excipients that may be included in topical as well as in other types of formulations (to the extent they are compatible), include preservatives, antioxidants, moisturizers, emollients, buffering agents, solubilizing agents, skin protectants, and surfactants. Suitable preservatives include alcohols, quaternary amines, organic acids, parabens, and phenols. Suitable antioxidants include ascorbic acid and its esters, sodium bisulfite, butylated hydroxytoluene, butylated hydroxyanisole, tocopherols, and chelating agents like EDTA and citric acid. Suitable moisturizers include glycerin, sorbitol, polyethylene glycols, urea, and propylene glycol. Suitable buffering agents include citric, hydrochloric, and lactic acid buffers. Suitable solubilizing agents include quaternary ammonium chlorides, cyclodextrins, benzyl benzoate, lecithin, and polysorbates. Suitable skin protectants include vitamin E oil, allatoin, dimethicone, glycerin, petrolatum, and zinc oxide.

Transdermal formulations typically employ transdermal delivery devices and transdermal delivery patches wherein the compound is formulated in lipophilic emulsions or buffered, aqueous solutions, dissolved and/or dispersed in a polymer or an adhesive. Patches may be constructed for continuous, pulsatile, or on demand delivery of pharmaceutical agents. Transdermal delivery of the compounds may be accomplished by means of an iontophoretic patch. Transdermal patches may provide controlled delivery of the compounds wherein the rate of absorption is slowed by using rate-controlling membranes or by trapping the compound within a polymer matrix or gel. Absorption enhancers may be used to increase absorption, examples of which include absorbable pharmaceutically acceptable solvents that assist passage through the skin.

Ophthalmic formulations include eye drops.

Formulations for rectal administration include enemas, rectal gels, rectal foams, rectal aerosols, and retention enemas, which may contain conventional suppository bases such as cocoa butter or other glycerides, as well as synthetic polymers such as polyvinylpyrrolidone, PEG, and the like. Compositions for rectal or vaginal administration may also be formulated as suppositories which can be prepared by mixing the compound with suitable non-irritating carriers and excipients such as cocoa butter, mixtures of fatty acid glycerides, polyethylene glycol, suppository waxes, and combinations thereof, all of which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the compound.

As used herein, the term, “therapeutically effective amount” refers to an amount of a compound of formula I or a pharmaceutically acceptable salt or a stereoisomer thereof that is effective in producing the desired therapeutic response in a particular patient suffering from a disease or disorder. The term “therapeutically effective amount” thus includes the amount of the compound of the invention or a pharmaceutically acceptable salt or a stereoisomer thereof, that when administered, induces a positive modification in the disease or disorder to be treated (e.g., to selectively inhibit/degrade IRAK1, IRAK4 or both IRAK1 and 4), or is sufficient to prevent development or progression of the disease or disorder, or alleviate to some extent, one or more of the symptoms of the disease or disorder being treated in a subject, or which simply kills or inhibits the growth of diseased (e.g., cancer) cells, or reduces the amount of IRAK1, IRAK4 or both RAK1 and 4 in diseased cells.

The total daily dosage of the compounds and usage thereof may be decided in accordance with standard medical practice, e.g., by the attending physician using sound medical judgment. Accordingly, the specific therapeutically effective dose for any particular subject may depend upon a variety of factors including the disease or disorder being treated and the severity thereof (e.g., its present status); the age, body weight, general health, sex and diet of the subject; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts (see, for example, Goodman and Gilman's, “The Pharmacological Basis of Therapeutics”, 10th Edition, A. Gilman, J. Hardman and L. Limbird, eds., McGraw-Hill Press, 155-173, 2001).

Compounds of formula I may be effective over a wide dosage range. In some embodiments, the total daily dosage (e.g., for adult humans) may range from about 0.001 to about 1000 mg, from 0.01 to about 1000 mg, from 0.01 to about 500 mg, from about 0.01 to about 100 mg, from about 0.5 to about 100 mg, from 1 to about 100-400 mg per day, from about 1 to about 50 mg per day, and from about 5 to about 40 mg per day, or in yet other embodiments from about 10 to about 30 mg per day. Individual dosages may be formulated to contain the desired dosage amount depending upon the number of times the compound is administered per day. By way of example, capsules may be formulated with from about 1 to about 200 mg of compound (e.g., 1, 2, 2.5, 3, 4, 5, 10, 15, 20, 25, 50, 100, 150, and 200 mg).

Methods of Use

In some aspects, the present invention is directed to methods of treating diseases or disorders involving dysfunctional or dysregulated IRAK1, IRAK4 or both IRAK1 and 4 activity, that entails administration of a therapeutically effective amount of a bispecific compound formula I or a pharmaceutically acceptable salt or stereoisomer thereof, to a subject in need thereof.

The diseases or disorders may be said to be characterized or mediated by dysfunctional IRAK1, IRAK4 or both IRAK1 and 4 activity (e.g., elevated levels of protein or otherwise functionally abnormal relative to a non-pathological state). A “disease” is generally regarded as a state of health of a subject wherein the subject cannot maintain homeostasis, and wherein if the disease is not ameliorated then the subject's health continues to deteriorate. In contrast, a “disorder” in a subject is a state of health in which the subject is able to maintain homeostasis, but in which the subject's state of health is less favorable than it would be in the absence of the disorder. Left untreated, a disorder does not necessarily cause a further decrease in the animal's state of health. In some embodiments, compounds of the invention may be useful in the treatment of cell proliferative diseases and disorders (e.g., cancer or benign neoplasms). As used herein, the term “cell proliferative disease or disorder” refers to the conditions characterized by deregulated or abnormal cell growth, or both, including noncancerous conditions such as neoplasms, precancerous conditions, benign tumors, and cancer.

The term “subject” (or “patient”) as used herein includes all members of the animal kingdom prone to or suffering from the indicated disease or disorder. In some embodiments, the subject is a mammal, e.g., a human or a non-human mammal. The methods are also applicable to companion animals such as dogs and cats as well as livestock such as cows, horses, sheep, goats, pigs, and other domesticated and wild animals. A subject “in need of” treatment according to the present invention may be “suffering from or suspected of suffering from” a specific disease or disorder may have been positively diagnosed or otherwise presents with a sufficient number of risk factors or a sufficient number or combination of signs or symptoms such that a medical professional could diagnose or suspect that the subject was suffering from the disease or disorder. Thus, subjects suffering from, and suspected of suffering from, a specific disease or disorder are not necessarily two distinct groups.

Exemplary types of non-cancerous (e.g., cell proliferative) diseases or disorders that may be amenable to treatment with the compounds of the present invention include inflammatory diseases and conditions, autoimmune diseases, neurodegenerative diseases, heart diseases, viral diseases, chronic and acute kidney diseases or injuries, atherosclerosis, obesity, metabolic diseases, and allergic and genetic diseases.

Representative examples of specific non-cancerous diseases and disorders include rheumatoid arthritis, alopecia areata, lymphoproliferative conditions, autoimmune hematological disorders (e.g. hemolytic anemia, aplastic anemia, anhidrotic ecodermal dysplasia, pure red cell anemia and idiopathic thrombocytopenia), cholecystitis, acromegaly, rheumatoid spondylitis, osteoarthritis, gout, scleroderma, sepsis, septic shock, dacryoadenitis, cryopyrin associated periodic syndrome (CAPS), endotoxic shock, endometritis, gram-negative sepsis, keratoconjunctivitis sicca, toxic shock syndrome, asthma, adult respiratory distress syndrome, chronic obstructive pulmonary disease, chronic pulmonary inflammation, chronic graft rejection, hidradenitis suppurativa, inflammatory bowel disease, Crohn's disease, Behcet's syndrome, systemic lupus erythematosus, multiple sclerosis, juvenile-onset diabetes, autoimmune uveoretinitis, autoimmune vasculitis, thyroiditis, Addison's disease, lichen planus, appendicitis, bullous pemphigus, pemphigus vulgaris, pemphigus foliaceus, paraneoplastic pemphigus, myasthenia gravis, immunoglobulin A nephropathy, autoimmune thyroditis or Hashimoto's disease, Sjogren's syndrome, vitiligo, Wegener granulamatosis, granulomatous orchitis, autoimmune oophoritis, sarcoidosis, rheumatic carditis, ankylosing spondylitis, Grave's disease, autoimmune thrombocytopenic purpura, psoriasis, psoriatic arthritis, eczema, dermatitis herpetiformis, ulcerative colitis, pancreatic fibrosis, hepatitis, hepatic fibrosis, CD14 mediated sepsis, non-CD14 mediated sepsis, acute and chronic renal disease, irritable bowel syndrome, pyresis, restenosis, cerebral malaria, cervicitis, stroke and ischemic injury, neural trauma, acute and chronic pain, allergic rhinitis, allergic conjunctivitis, chronic heart failure, congestive heart failure, acute coronary syndrome, cachexia, malaria, leprosy, leishmaniasis, Lyme disease, Reiter's syndrome, acute synovitis, muscle degeneration, bursitis, tendonitis, tenosynovitis, herniated, ruptured, or prolapsed intervertebral disk syndrome, osteopetrosis, thrombosis, restenosis, silicosis, pulmonary sarcosis, bone resorption diseases, such as osteoporosis, graft-versus-host reaction, fibromyalgia, AIDS and other viral diseases such as Herpes Zoster, Herpes Simplex I or II, influenza virus and cytomegalovirus, diabetes Type I and II, obesity, insulin resistance and diabetic retinopathy, 2211.2 deletion syndrome, Angelman syndrome, Canavan disease, celiac disease, Charcot-Marie-Tooth disease, color blindness, Cri du chat, Down syndrome, cystic fibrosis, Duchenne muscular dystrophy, haemophilia, Klinefleter's syndrome, neurofibromatosis, phenylketonuria, Prader-Willi syndrome, sudden infant death syndrome, sickle cell disease, Tay-Sachs disease, Turner syndrome, urea cycle disorders, thalassemia, otitis, pancreatitis, parotitis, pericarditis, peritonitis, pharyngitis, pleuritis, phlebitis, pneumonitis, cystic fibrosis, uveitis, polymyositis, proctitis, interstitial lung fibrosis, dermatomyositis, arteriosclerosis, amyotrophic lateral sclerosis, asocality, immune response, varicosis, vaginitis, including chronic recurrent yeast vaginitis, depression, Sudden Infant Death Syndrome, and varicosis.

In other embodiments, the methods are directed to treating subjects having cancer. Broadly, the compounds of the present invention may be effective in the treatment of carcinomas (solid tumors including both primary and metastatic tumors), sarcomas, melanomas, and hematological cancers (cancers affecting blood including lymphocytes, bone marrow and/or lymph nodes) such as leukemia, lymphoma and multiple myeloma. Adult tumors/cancers and pediatric tumors/cancers are included. The cancers may be vascularized, or not yet substantially vascularized, or non-vascularized tumors.

Representative examples of cancers includes adenocortical carcinoma, AIDS-related cancers (e.g., Kaposi's and AIDS-related lymphoma), appendix cancer, childhood cancers (e.g., childhood cerebellar astrocytoma, childhood cerebral astrocytoma), basal cell carcinoma, skin cancer (non-melanoma), biliary cancer, extrahepatic bile duct cancer, intrahepatic bile duct cancer, bladder cancer, urinary bladder cancer, brain cancer (e.g., gliomas and glioblastomas such as brain stem glioma, cerebellar astrocytoma, cerebral astrocytoma/malignant glioma, ependymoma, medulloblastoma, supratentorial primitive neuroectodeimal tumors, visual pathway and hypothalamic glioma), breast cancer, bronchial adenomas/carcinoids, carcinoid tumor, nervous system cancer (e.g., central nervous system cancer, central nervous system lymphoma), cervical cancer, chronic myeloproliferative disorders, colorectal cancer (e.g., colon cancer, rectal cancer), lymphoid neoplasm, mycosis fungoids, Sezary Syndrome, endometrial cancer, esophageal cancer, extracranial germ cell tumor, extragonadal germ cell tumor, extrahepatic bile duct cancer, eye cancer, intraocular melanoma, retinoblastoma, gallbladder cancer, gastrointestinal cancer (e.g., stomach cancer, small intestine cancer, gastrointestinal carcinoid tumor, gastrointestinal stromal tumor (GIST)), germ cell tumor, ovarian germ cell tumor, gestational trophoblastic tumor glioma, head and neck cancer, Hodgkin's lymphoma, leukemia, lymphoma, multiple myeloma, hypopharyngeal cancer, intraocular melanoma, ocular cancer, islet cell tumors (endocrine pancreas), renal cancer (e.g., Wilm's Tumor, clear cell renal cell carcinoma), liver cancer, lung cancer (e.g., non-small cell lung cancer and small cell lung cancer), Waldenstrom's macroglobulinema, melanoma, intraocular (eye) melanoma, merkel cell carcinoma, mesothelioma, metastatic squamous neck cancer with occult primary, multiple endocrine neoplasia (MEN), myelodysplastic syndromes, myelodyplastic/myeloproliferative diseases, nasopharyngeal cancer, neuroblastoma, oral cancer (e.g., mouth cancer, lip cancer, oral cavity cancer, tongue cancer, oropharyngeal cancer, throat cancer, laryngeal cancer), ovarian cancer (e.g., ovarian epithelial cancer, ovarian germ cell tumor, ovarian low malignant potential tumor), pancreatic cancer, islet cell pancreatic cancer, paranasal sinus and nasal cavity cancer, parathyroid cancer, penile cancer, pharyngeal cancer, pheochromocytoma, pineoblastoma, pituitary tumor, plasma cell neoplasm/multiple myeloma, pleuropulmonary blastoma, prostate cancer, retinoblastoma rhabdomyosarcoma, salivary gland cancer, uterine cancer (e.g., endometrial uterine cancer, uterine sarcoma, uterine corpus cancer), squamous cell carcinoma, testicular cancer, thymoma, thymic carcinoma, thyroid cancer, transitional cell cancer of the renal pelvis and ureter and other urinary organs, urethral cancer, gestational trophoblastic tumor, vaginal cancer and vulvar cancer.

Sarcomas that may be treatable with compounds of the present invention include both soft tissue and bone cancers alike, representative examples of which include osteosarcoma or osteogenic sarcoma (bone) (e.g., Ewing's sarcoma), chondrosarcoma (cartilage), leiomyosarcoma (smooth muscle), rhabdomyosarcoma (skeletal muscle), mesothelial sarcoma or mesothelioma (membranous lining of body cavities), fibrosarcoma (fibrous tissue), angiosarcoma or hemangioendothelioma (blood vessels), liposarcoma (adipose tissue), glioma or astrocytoma (neurogenic connective tissue found in the brain), myxosarcoma (primitive embryonic connective tissue) and mesenchymous or mixed mesodermal tumor (mixed connective tissue types).

In some embodiments, methods of the present invention entail treatment of subjects having cell proliferative diseases or disorders of the hematological system, liver (hepatocellular), brain, lung, colorectal (e.g., colon), pancreas, prostate, skin, ovary, breast, skin (e.g., melanoma), and endometrium.

As used herein, “cell proliferative diseases or disorders of the hematologic system” include lymphoma, leukemia, myeloid neoplasms, mast cell neoplasms, myelodysplasia, benign monoclonal gammopathy, lymphomatoid papulosis, polycythemia vera, chronic myelocytic leukemia, agnogenic myeloid metaplasia, and essential thrombocythemia. Representative examples of hematologic cancers may thus include multiple myeloma, lymphoma (including T-cell lymphoma, Hodgkin's lymphoma, non-Hodgkin's lymphoma (diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), mantle cell lymphoma (MCL) and ALK+anaplastic large cell lymphoma (e.g., B-cell non-Hodgkin's lymphoma selected from diffuse large B-cell lymphoma (e.g., germinal center B-cell-like diffuse large B-cell lymphoma or activated B-cell-like diffuse large B-cell lymphoma), Burkitt's lymphoma/leukemia, mantle cell lymphoma, mediastinal (thymic) large B-cell lymphoma, follicular lymphoma, marginal zone lymphoma, lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia, refractory B-cell non-Hodgkin's lymphoma, and relapsed B-cell non-Hodgkin's lymphoma, childhood lymphomas, and lymphomas of lymphocytic and cutaneous origin, e.g., small lymphocytic lymphoma, primary CNS lymphoma (PCNSL), marginal zone lymphoma (MZL), leukemia, including chronic lymphocytic leukemia (CLL), childhood leukemia, hairy-cell leukemia, acute lymphocytic leukemia, acute myelocytic leukemia, acute myeloid leukemia (e.g., acute monocytic leukemia), chronic lymphocytic leukemia, small lymphocytic leukemia, chronic myelocytic leukemia, chronic myelogenous leukemia, and mast cell leukemia, myeloid neoplasms and mast cell neoplasms.

As used herein, “cell proliferative diseases or disorders of the lung” include all forms of cell proliferative disorders affecting lung cells. Cell proliferative disorders of the lung include lung cancer, precancer and precancerous conditions of the lung, benign growths or lesions of the lung, hyperplasia, metaplasia, and dysplasia of the long, and metastatic lesions in the tissue and organs in the body other than the lung. Lung cancer includes all forms of cancer of the lung, e.g., malignant lung neoplasms, carcinoma in situ, typical carcinoid tumors, and atypical carcinoid tumors. Lung cancer includes small cell lung cancer (“SLCL”), non-small cell lung cancer (“NSCLC”), squamous cell carcinoma, adenocarcinoma, small cell carcinoma, large cell carcinoma, squamous cell carcinoma, and mesothelioma. Lung cancer can include “scar carcinoma”, bronchioveolar carcinoma, giant cell carcinoma, spindle cell carcinoma, and large cell neuroendocrine carcinoma. Lung cancer also includes lung neoplasms having histologic and ultrastructural heterogeneity (e.g., mixed cell types).

As used herein, “cell proliferative diseases or disorders of the colon” include all forms of cell proliferative disorders affecting colon cells, including colon cancer, a precancer or precancerous conditions of the colon, adenomatous polyps of the colon and metachronous lesions of the colon. Colon cancer includes sporadic and hereditary colon cancer, malignant colon neoplasms, carcinoma in situ, typical carcinoid tumors, and atypical carcinoid tumors, adenocarcinoma, squamous cell carcinoma, and squamous cell carcinoma. Colon cancer can be associated with a hereditary syndrome such as hereditary nonpolyposis colorectal cancer, familiar adenomatous polyposis, MYH associated polypopsis, Gardner's syndrome, Peutz-Jeghers syndrome, Turcot's syndrome and juvenile polyposis. Cell proliferative disorders of the colon may also be characterized by hyperplasia, metaplasia, or dysplasia of the colon.

As used herein, “cell proliferative diseases or disorders of the pancreas” include all forms of cell proliferative disorders affecting pancreatic cells. Cell proliferative disorders of the pancreas may include pancreatic cancer, a precancer or precancerous condition of the pancreas, hyperplasia of the pancreas, dysplasia of the pancreas, benign growths or lesions of the pancreas, and malignant growths or lesions of the pancreas, and metastatic lesions in tissue and organs in the body other than the pancreas. Pancreatic cancer includes all forms of cancer of the pancreas, including ductal adenocarcinoma, adenosquamous carcinoma, pleomorphic giant cell carcinoma, mucinous adenocarcinoma, osteoclast-like giant cell carcinoma, mucinous cystadenocarcinoma, acinar carcinoma, unclassified large cell carcinoma, small cell carcinoma, pancreatoblastoma, papillary neoplasm, mucinous cystadenoma, papillary cystic neoplasm, and serous cystadenoma, and pancreatic neoplasms having histologic and ultrastructural heterogeneity (e.g., mixed cell types).

As used herein, “cell proliferative diseases or disorders of the prostate” include all forms of cell proliferative disorders affecting the prostate. Cell proliferative disorders of the prostate may include prostate cancer, a precancer or precancerous condition of the prostate, benign growths or lesions of the prostate, and malignant growths or lesions of the prostate, and metastatic lesions in tissue and organs in the body other than the prostate. Cell proliferative disorders of the prostate may include hyperplasia, metaplasia, and dysplasia of the prostate.

As used herein, “cell proliferative diseases or disorders of the skin” include all forms of cell proliferative disorders affecting skin cells. Cell proliferative disorders of the skin may include a precancer or precancerous condition of the skin, benign growths or lesions of the skin, melanoma, malignant melanoma or other malignant growths or lesions of the skin, and metastatic lesions in tissue and organs in the body other than the skin. Cell proliferative disorders of the skin may include hyperplasia, metaplasia, and dysplasia of the skin.

As used herein, “cell proliferative diseases or disorders of the ovary” include all forms of cell proliferative disorders affecting cells of the ovary. Cell proliferative disorders of the ovary may include a precancer or precancerous condition of the ovary, benign growths or lesions of the ovary, ovarian cancer, and metastatic lesions in tissue and organs in the body other than the ovary. Cell proliferative disorders of the ovary may include hyperplasia, metaplasia, and dysplasia of the ovary.

As used herein, “cell proliferative diseases or disorders of the breast” include all forms of cell proliferative disorders affecting breast cells. Cell proliferative disorders of the breast may include breast cancer, a precancer or precancerous condition of the breast, benign growths or lesions of the breast, and metastatic lesions in tissue and organs in the body other than the breast. Cell proliferative disorders of the breast may include hyperplasia, metaplasia, and dysplasia of the breast.

In some embodiments, the compounds or pharmaceutically acceptable salts or stereoisomers of the present invention are used in the treatment of high-risk neuroblastoma (NB).

In some embodiments, the disease or disorder is acute myeloid leukemia (AML), multiple myeloma (MM), melanoma, rhabdomyosarcoma, or diffuse large B cell lymphoma. In other embodiments, the disease or disorder is small solid tumor. In other embodiments, the disease or disorder is colon cancer, rectum cancer, stomach cancer, breast cancer or pancreatic cancer.

In some embodiments, a bifunctional compound of the present invention may be used to treat lung cancer (e.g., NSLC), advanced and metastatic solid tumors, ALK-positive anaplastic large cell lymphoma, central nervous system tumors, neuroblastoma, breast cancer, cholangiocarcinoma, colorectal cancer, head and neck neoplasms, neuroendocrine tumors, ovarian cancer, pancreatic cancer, papillary thyroid cancer, primary brain tumors, renal cell carcinoma, Sarcomas, salivary gland cancers, metastatic anaplastic thyroid cancer, undifferentiated thyroid cancer, glioblastoma, brain metastases, advanced malignant solid neoplasm, metastatic pancreatic adenocarcinoma, stage III and IV pancreatic cancer, melanoma (advanced and unresectable), CD30-positive neoplastic cells, BRAF/NRAS wild-type stage III-IV melanoma, advanced, refractory, and recurrent malignant solid neoplasm, Ann Arbor stage III and stage IV childhood Non-Hodgkin's lymphoma, histiocytosis, recurrent childhood central nervous system neoplasm and Non-Hodgkin's lymphoma, refractory central nervous system neoplasm, ROS-positive refractory Non-Hodgkin's lymphoma, childhood Langerhans cell histiocytosis, histiocytic sarcoma, juvenile xanthogranuloma, malignant glioma, recurrent childhood ependymoma, malignant germ cell tumor and medulloblastoma, recurrent childhood Non-Hodgkin's lymphoma, rhabdomyosarcoma, and soft tissue sarcoma, recurrent Ewing sarcoma, glioma, hepatoblastoma, neuroblastoma, osteosarcoma, and peripheral primitive neuroectodermal tumor, refractory Central nervous system neoplasm, rhabdoid tumor, stage III and IV osteosarcoma AJCC v7, stage III and IV soft tissue sarcoma AJCC v7, stage IVA and IVB osteosarcoma AJCC v7, and Wilm's tumor.

The compounds of formula (I) of the present invention may be administered to a patient, e.g., a cancer patient, as a monotherapy or by way of combination therapy, and as a front-line therapy or a follow-on therapy for patients who are unresponsive to front line therapy. Therapy may be “first-line”, i.e., as an initial treatment in patients who have undergone no prior anti-cancer treatment regimens, either alone or in combination with other treatments; or “second-line”, as a treatment in patients who have undergone a prior anti-cancer treatment regimen, either alone or in combination with other treatments; or as “third-line”, “fourth-line”, etc. treatments, either alone or in combination with other treatments. Therapy may also be given to patients who have had previous treatments which have been partially successful but are intolerant to the particular treatment. Therapy may also be given as an adjuvant treatment, i.e., to prevent reoccurrence of cancer in patients with no currently detectable disease or after surgical removal of a tumor. Thus, in some embodiments, the compound may be administered to a patient who has received another therapy, such as chemotherapy, radioimmunotherapy, surgical therapy, immunotherapy, radiation therapy, targeted therapy or any combination thereof.

The methods of the present invention may entail administration of compounds of formula I of the invention or pharmaceutical compositions thereof to the patient in a single dose or in multiple doses (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 10, 15, 20, or more doses). For example, the frequency of administration may range from once a day up to about once every eight weeks. In some embodiments, the frequency of administration ranges from about once a day for 1, 2, 3, 4, 5, or 6 weeks, and in other embodiments entails a 28-day cycle which includes daily administration for 3 weeks (21 days). In other embodiments, the bifunctional compound may be dosed twice a day (BID) over the course of two and a half days (for a total of 5 doses) or once a day (QD) over the course of two days (for a total of 2 doses). In other embodiments, the bifunctional compound may be dosed once a day (QD) over the course of five days.

Combination Therapy

The compounds of formula I of the present invention may be used in combination or concurrently with at least one other active agent, e.g., anti-cancer agent or regimen, in treating diseases and disorders. The terms “in combination” and “concurrently in this context mean that the agents are co-administered, which includes substantially contemporaneous administration, by way of the same or separate dosage forms, and by the same or different modes of administration, or sequentially, e.g., as part of the same treatment regimen, or by way of successive treatment regimens. Thus, if given sequentially, at the onset of administration of the second compound, the first of the two compounds is in some cases still detectable at effective concentrations at the site of treatment. The sequence and time interval may be determined such that they can act together (e.g., synergistically to provide an increased benefit than if they were administered otherwise). For example, the therapeutics may be administered at the same time or sequentially in any order at different points in time; however, if not administered at the same time, they may be administered sufficiently close in time so as to provide the desired therapeutic effect, which may be in a synergistic fashion. Thus, the terms are not limited to the administration of the active agents at exactly the same time.

In some embodiments, the treatment regimen may include administration of a compound of formula I of the invention in combination with one or more additional therapeutics known for use in treating the disease or condition (e.g., cancer). The dosage of the additional anticancer therapeutic may be the same or even lower than known or recommended doses. See, Hardman et al., eds., Goodman & Gilman's The Pharmacological Basis Of Basis Of Therapeutics, 10th ed., McGraw-Hill, New York, 2001; Physician's Desk Reference 60th ed., 2006. For example, anti-cancer agents that may be used in combination with the inventive compounds are known in the art. See, e.g., U.S. Pat. No. 9,101,622 (Section 5.2 thereof) and U.S. Pat. No. 9,345,705 B2 (Columns 12-18 thereof). Representative examples of additional active agents and treatment regimens include radiation therapy, chemotherapeutics (e.g., mitotic inhibitors, angiogenesis inhibitors, anti-hormones, autophagy inhibitors, alkylating agents, intercalating antibiotics, growth factor inhibitors, anti-androgens, signal transduction pathway inhibitors, anti-microtubule agents, platinum coordination complexes, HDAC inhibitors, proteasome inhibitors, and topoisomerase inhibitors), immunomodulators, therapeutic antibodies (e.g., mono-specific and bispecific antibodies) and CAR-T therapy.

In some embodiments, the compound of formula I of the invention and the additional anticancer therapeutic may be administered less than 5 minutes apart, less than 30 minutes apart, less than 1 hour apart, at about 1 hour apart, at about 1 to about 2 hours apart, at about 2 hours to about 3 hours apart, at about 3 hours to about 4 hours apart, at about 4 hours to about 5 hours apart, at about 5 hours to about 6 hours apart, at about 6 hours to about 7 hours apart, at about 7 hours to about 8 hours apart, at about 8 hours to about 9 hours apart, at about 9 hours to about 10 hours apart, at about 10 hours to about 11 hours apart, at about 11 hours to about 12 hours apart, at about 12 hours to 18 hours apart, 18 hours to 24 hours apart, 24 hours to 36 hours apart, 36 hours to 48 hours apart, 48 hours to 52 hours apart, 52 hours to 60 hours apart, 60 hours to 72 hours apart, 72 hours to 84 hours apart, 84 hours to 96 hours apart, or 96 hours to 120 hours part. The two or more anticancer therapeutics may be administered within the same patient visit.

In some embodiments, the compound of formula I of the present invention and the additional agent or therapeutic (e.g., an anti-cancer therapeutic) are cyclically administered. Cycling therapy involves the administration of one anticancer therapeutic for a period of time, followed by the administration of a second anti-cancer therapeutic for a period of time and repeating this sequential administration, i.e., the cycle, in order to reduce the development of resistance to one or both of the anticancer therapeutics, to avoid or reduce the side effects of one or both of the anticancer therapeutics, and/or to improve the efficacy of the therapies. In one example, cycling therapy involves the administration of a first anticancer therapeutic for a period of time, followed by the administration of a second anticancer therapeutic for a period of time, optionally, followed by the administration of a third anticancer therapeutic for a period of time and so forth, and repeating this sequential administration, i.e., the cycle in order to reduce the development of resistance to one of the anticancer therapeutics, to avoid or reduce the side effects of one of the anticancer therapeutics, and/or to improve the efficacy of the anticancer therapeutics.

For example, in some embodiments where a compound of the present invention is used to treat cancer, e.g., a hematopoietic cancer, the additional anticancer therapeutic may be an inhibitor or Burton's tyrosine kinase (BTK) such as ibrutinib. Ibrutinib is a small molecule drug that binds to BTK, and is used to treat B cell cancers such as mantle cell lymphoma, chronic lymphocytic leukemia, and Waldenstrom's macroglobulinemia. The dosage of ibrutinib may be the same or even lower than known or recommended doses (e.g., 420-560 mg taken orally once daily). Additional BTK inhibitors that may be used in combination with compounds of the present invention are disclosed in U.S. Patent Publication No. 2017/0035881.

Pharmaceutical Kits

The present compositions may be assembled into kits or pharmaceutical systems. Kits or pharmaceutical systems according to this aspect of the invention include a carrier or package such as a box, carton, tube or the like, having in close confinement therein one or more containers, such as vials, tubes, ampoules, or bottles, which contain the compound of formula I of the present invention or a pharmaceutical composition. The kits or pharmaceutical systems of the invention may also include printed instructions for using the compounds and compositions.

These and other aspects of the present invention will be further appreciated upon consideration of the following Examples, which are intended to illustrate certain particular embodiments of the invention but are not intended to limit its scope, as defined by the claims.

EXAMPLES Example 1: Synthesis of compound [0180] N-(3-(1-(3-(2-(2-((2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl)amino)ethoxy)ethoxy)propanoyl)piperidin-4-yl)-1-(pyridin-2-yl-1H-pyrazol-5-yl)-6-(1H-pyrazol-5-yl)picolinamide (2)

The reaction scheme for synthesizing compound 2 is set forth below.

tert-Butyl 4-(5-amino-1-(pyridin-2-yl)-1H-pyrazol-3-yl)piperidine-1-carboxylate (A)

The starting material, compound A, was prepared according to the procedure disclosed in McElroy et al., ACS Med. Chem. Let. 6(6):677-82 (2015).

tert-Butyl 4-(5-(6-bromopicolinamido)-1-(pyridin-2-yl)-1H-pyrazol-3-yl)piperidine-1-carboxylate (C)

To a solution of 6-bromopicolinic acid (B) (0.5 g, 2.48 mmol) in DCM (20 mL) was added oxalyl chloride (1.06 mL, 12.4 mmol), followed by 3 drops of DMF. The solution was stirred for 1 hour at room temperature (rt), then the solvent was removed and the residue dissolved in THF (10 mL). tert-Butyl 4-(5-amino-(pyridin-2-yl)-1H-pyrazol-3-yl)piperidine-1-carboxylate (0.94 g, 2.72 mmol) was added along with saturated aqueous NaHCO₃(5 mL). The mixture was stirred for 30 minutes and then was quenched with H₂O. The resulting mixture was extracted with EtOAc, dried over anhydrous MgSO₄, and condensed under reduced pressure to give a light-brown solid. The crude product was purified by flash chromatography (FC) using a gradient of 40% to 90% EtOAc in hexanes to give compound C as a white solid (649 mg, 50% yield).

MS m/z 527.5 [M+H]⁺.

N-(3-(piperidin-4-yl)-1-(pyridin-2-yl)-1H-pyrazol-5-yl)-6-(1H-pyrazol-5-yl)picolinamide (D)

tert-Butyl 4-(5-(6-bromopicolinamido)-1-(pyridin-2-yl)-1H-pyrazol-3-yl)piperidine-1-carboxylate (260 mg, 0.496 mmol) and 1-(tetrahydro-2H-pyran-2-yl)-5-(4,4,5,5-tetramethyl-1,3-dioxolan-2-yl)-1H-pyrazole (152 mg, 0.545 mmol) were dissolved in 1,4-dioxane (10 mL) along with 2 M Na₂CO₃ (1.24 mL) in a reaction vial. The mixture was degassed in a sonicator, and Pd(dppf)Cl₂ (44 mg, 0.06 mmol) and t-BuXPhos (41 mg, 0.09 mmol) were added. The vial was flushed with N₂, sealed and stirred at 100° C. for 1 hour. The mixture was quenched with H₂O, extracted with EtOAc, dried of MgSO₄ and condensed under reduced pressure to give a brown oil. To a solution of the brown oily product in DCM (10 mL), TFA (1 mL) was added and the mixture was stirred for 1 hour. The solvent was removed and the residue was purified by reverse phase HPLC to give the desired product as a beige solid (180 mg, 87% yield).

MS m/z 415.63 [M+H]⁺.

Compound 2

N-(3-(piperidin-4-yl)-1-(pyridin-2-yl)-1H-pyrazol-5-yl)-6-(1H-pyrazol-5-yl)picolinamide (20 mg, 0.048 mmol) (D), 3-(2-(2-((2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl)amino)ethoxy)ethoxy)propanoic acid (E) (23 mg, 0.053 mmol) and 1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate (HATU) (36 mg, 0.096 mmol) were dissolved in DMF (1.5 mL). N,N-diisopropylethylamine (DIEA) (42 μL, 0.24 mmol) was added and the mixture was stirred for 30 minutes. The residue was purified by reverse phase HPLC to give the desired compound as a yellow solid (6 mg, 15% yield).

MS m/z 830. 71 [M+H]⁺.

Example 2: Synthesis of N-(3-(1-(1-((2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl)amino)-3,6,9,12-tetraoxapentadecan-15-oyl)piperidin-4-yl)-1-(pyridin-2-yl)-1H-pyrazol-5-yl)-6-(1H-pyrazol-5-yl)picolinamide (1)

Compound 1

The title compound was prepared in an analogous manner to compound 2 in Example 1 as a yellow solid (18 mg, 41% yield).

MS m/z 917. 82 [M+H]⁺.

Example 3: Synthesis of N-(3-(1-(3-(2-(2-((2-(2,6-dioxoiperidin-3-yl)-1-oxoisoindolin-4-yl)amino)ethoxy)ethoxy)propanoyl)piperidin-4-yl)-1-(pyridin-2-yl)-1H-pyrazol-5-yl)-6-(1H-pyrazol-5-yl)picolinamide (3)

Compound 3

The title compound was prepared in an analogous manner to compound 2 in Example 1 as a brown solid (7 mg, 18% yield).

MS m/z 816.34 [M+H]⁺.

Example 8: Synthesis of N-(3-1-(9-((2-(2,6-dioxopiperidin-3-yl)-1,3-dioxoisoindolin-4-yl)oxy)nonanoyl)piperidin-4-yl)-1-(pyridin-2-yl)-1H-pyrazol-5-yl)-6-(1H-pyrazol-5-yl)picolinamide (4)

Compound 4

The title compound was prepared in an analogous manner to compound 2 in Example 1 as a yellow solid (8 mg, 21% yield).

MS m/z 826.78 [M+H]⁺.

Example 5: IRAK1 and IRAK 4 IC₅₀ Values for Inventive Compounds

The IRAK1 and IRAK 4 IC₅₀ values for various compounds disclosed herein generated from an Adapta® kinase assay format, and a Z′-LYTE™ kinases assay format, respectively, are shown in Table 1.

TABLE 1 Compound IRAK1 IC₅₀ IRAK4 IC₅₀ 1 43 nM 16 nM 2 42 nM 44 nM 3 40 nM 18 nM 4 212 nM 142 nM T_(L1) 7 nM 3 nM T_(L2) 9 nM >10 μM

The data in Table 1 shows the biochemical IC₅₀'s for the IRAK14 degraders as well as the core inhibitors. This data indicates that the IRAK1/4 degraders maintain tight binding to the enzyme and therefore reinforces the notion that cellular potency is due to on-target degradation of IRAK1/4 and not some off-target effect.

Example 6: ED₅₀ in BCWM.1, MWCL-1, TMD*, HBL-1, OCI-Ly7, and OCI-Ly19 Cells for Inventive Compounds

The ED₅₀ in various WM (BCWM.1 cell lines, MWCL-1 cell lines) and DLBCL (TMD*cell lines, HBL-1 cell lines, OCI-Ly7 cell lines, OCI-Ly19 cell lines) cells was determined for the degrader compounds (CPDs) as shown in Table 2.

TABLE 2 ED 50 CPD 1 CPD 2 CPD 3 CPD 4 CPD T_(L2) BCWM.1 7.08E−08 1.20E−05 1.16E−05 1085E−03 4.73E−06 MWCL-1 3.75E−07 4.46E−06 6.81E−06 3.11E−05 1.12E−05 TMD8 4.50E−09 3.42E−06 5.84E−06 1.07E−05 8.29E−06 HBL-1 2.91E−07 8.06E−06 1.04E−05 2.73E−05 1.20E−05 OCI-Ly7 1.37E−08 8.79E−06 8.39E−06 3.03E−04 6.45E−06 OCI-Ly19 2.46E−09 9.43E−07 6.48E−06 2.59E−05 1.56E−06 Ramos cells 9.64E−08 1.46E−06 9.11E−06 2.79E−06 1.40E−06 (B lymphocytes; Burkitt’s Lymphoma) RPMI-8226 cells 3.22E−06 3.76E−04 1.47E−05 9.60E+02 2.27E−05 (lymphoblasts; multiple myeloma)

The data in Table 2 shows that the IRAK1/4 degrader CPDIJis more potent in the tested cells than the parental inhibitor TL2, which indicates an enhanced killing effect via degradation compared to inhibition alone.

Compound 1 (with aPEG-4 linker and pomalidomide degron) was much more potent in a panel of WM and DLBCL cells than compounds with shorter PEG-2 linkers, compounds 2 and 3, or an O-octyl linker, compound 4. The highly selective IRAK1 inhibitor, compound (TL2), was also much less potent than compound 1.

Example 7: In Vitro Cellular Efficacy Assessments

The in vitro cellular efficacies of IRAK1/4 degraders or inhibitors were assessed using CellTiter-Glo® Luminescent cell viability assay (Promega, Madison Wis.). Cells were seeded into 384 well plates with the EL406 Combination Washer Dispenser (BioTek Instruments, Inc.) and IRAK/4 degraders or inhibitors were injected into the cells culture media with the JANUS Automated Workstation (PerkinElmer Inc., Waltham Mass.). Cells were treated with serial diluted IRAK1/4 degraders or inhibitors (20˜0.0006 μM) for 72 hours at 37° C. Luminescent measurement was performed using the 2104 Envision® Multilabel Reader (PerkinElmer Inc.). The dose-response curves and cellular efficacies were calculated compared to vehicle DMSO control with Graphpad Prism software. The results are shown in FIG. 1A-FIG. 2D.

Example 8: ED₅₀ in BCWM.1, MWCL-1, TMD*, HBL-1, OCI-Ly7, and OCI-Ly19 Cells for Inventive Compounds and Controls

A negative control for the degrader compounds of the present invention was prepared with a compound of formula C1:

A methyl substitution on the nitrogen of the pyridinyl group of the degron portion of C1 abolishes binding to cereblon.

The ED₅₀ in various WM and DLBCL cells was determined for the control compounds, the IRAK1/4 inhibitor, compound TL1, and the negative control, compound C1 as shown in Table 3.

TABLE 3 ED₅₀ CPD C1 CPD T_(L1) CPD 1 BCWM.1 1.67E−05 1.19E−06 6.96E−09 MWCL-1 1.91E−05 2.19E−06 1.57E−05 TMD8 1.23E−05 1.05E−06 9.55E−09 HBL-1 6.89E−06 6.01E−07 3.04E−08 OCI-Ly7 8.41E−06 1.43E−06 2.30E−08 OCI-Ly19 1.12E−05 2.91E−07 2.93E−09 Ramos 5.64E−06 2.74E−07 9.27E−08

As shown in Table 3, the dual IRAK/4 inhibitor, compound TL1, was much less potent in the panel of WM and DLBCL cells compared to compound 1 despite having single digit nM IC₅₀ 's against IRAK1 and IRAK4, indicating the enhanced cellular potency is due to degradation of IRAK 1/4 and not inhibition. In addition, the negative control compound C1, which cannot bind cereblon, was also much less potent in the panel of WM and DLBCL cells, further supporting the conclusion that the enhanced cellular potency of compound 1 is due to degradation of IRAK1/4.

PhosFlow® Analysis

PhosFlow® analysis was performed to detect the levels of IRAK1 phosphorylation at position Threonine 209 (T209) or IRAK4 phosphorylation at positions of Threonine 345 and Serine 346 (T345/S346). Cells were fixed with BD PhosFlow™ Fix Buffer I at 37° C. for 10 min, then centrifuged (350×g for 5 min) and washed twice with PhosFlow™ Perm/Wash Buffer I (BD Pharmingen™). Cells were then stained with anti-IRAK (phospho T209) antibody (Abcam@, Cambridge Mass.) or PE Conjugated anti-IRAK4 (phospho T345/S346) antibody for 30 min at room temperature, then washed thrice with BD PhosFlow™ Perm/Wash Buffer I. If secondary antibody is needed, cells then were incubated with anti-Rabbit IgG DyLight®-649 secondary antibody (Abcam®) for an additional 30 min. Cells were then washed twice with BD™ Perm/Wash Buffer I and flow analysis performed using a BD™ FACSCanto 11 Flow Cytometer. Flow data was analyzed using FlowJo® software. The data is shown in FIG. 3A and FIG. 3B.

Immunoblotting

The degradation of IRAK1 or IRAK4 proteins in BCWM.1 cells was determined by immunoblotting using BCWM.1 total cell lysates prepared following overnight treatment with IRAK1/4 degraders or inhibitors using anti-IRAK1 and anti-IRAK4 antibodies (Cell Signaling Technologies, Danvers Mass.). Anti-GAPDH antibody (Santa Cruz Biotechnology) was used for determination of protein loading.

As shown in FIG. 4, compound 1 degraded IRAK1 and IRAK4 in BCWM.1 cells, while the negative control showed no degradation at concentrations as high as 10 μM. The IRAK1/4 inhibitor, compound TL1, had no effect on IRAK 1 or IRAK4 protein levels at a concentration of 10 μM.

All publications cited in the specification, including patent publications and non-patent publications, are indicative of the level of skill of those skilled in the art to which this invention pertains. All these publications are herein incorporated by reference to the same extent as if each individual publication were specifically and individually indicated as being incorporated by reference.

Although the invention described herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principle and applications described herein. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the various embodiments described herein as defined by the appended claims. 

1. A bifunctional compound having a structure represented by formula I:

wherein the targeting ligand represents a moiety that binds Interleukin-1 receptor kinase 1 (IRAK1), interleukin-1 receptor kinase 4 (IRAK4) or both IRAK1 and IRAK4 (IRAK/4), the degron represents a moiety that binds an E3 ubiquitin ligase, and the linker represents a moiety that covalently connects the degron and the targeting ligand, or a pharmaceutically acceptable salt or stereoisomer thereof.
 2. The bifunctional compound of claim 1, wherein the targeting ligand is represented by any one of structures (TL1-a)-(TL11-c):

wherein R is H or methyl,


3. (canceled)
 4. The bifunctional compound of claim 1, wherein the linker is represented by any one of structures L7-L7d:

wherein R_(L2) is NH or CO, m is 1, n is 2-4, R_(L1) is RaCO, Ra is C₂ alkyl or


5. (canceled)
 6. The bifunctional compound of claim 1, wherein the degron binds the E3 ubiquitin ligase which is cereblon.
 7. The bifunctional compound of claim 6, wherein the degron is represented by any one of structures D1-Did:

wherein Y is a bond, N, O, S, (CH₂)₁₋₆, (CH₂)₀₋₆—O, (CH₂)₀₋₆—C(O)NR_(2′), (CH₂)₀₋₆—NR_(2′)C(O), (CH₂)₀₋₆—NH, or (CH₂)₀₋₆—NR₂; X is C(O) or C(R₆)₂; X′ is NH or CH₂; each R₁ is independently halogen, OH, C₁-C₆ alkyl, or C₁-C₆ alkoxy; each R₃ is independently H or C₁-C₃ alkyl; each R₂ is independently H or C₁-C₃ alkyl; each R₄ is independently H or C₁-C₃ alkyl; or R₂ and R₄, together with the carbon atom to which they are attached, form C(O), a C₃-C₆ carbocycle, or a 4-, 5-, or 6-membered heterocycle comprising 1 or 2 heteroatoms selected from N and O; R₅ is H, deuterium, C₁-C₃ alkyl, F, or Cl; R₆ is H or C₁-C₃ alkyl; m is 0, 1, 2 or 3; and n is 0, 1 or 2,


8. (canceled)
 9. The bifunctional compound of claim 1, wherein the degron binds the E3 ubiquitin ligase which is von Hippel-Landau tumor suppressor.
 10. The bifunctional compound of claim 9, wherein the degron is represented by any one of structures D2a-D2d:

wherein Y′ is a bond, N, O or C; and

wherein Z is a cyclic group.
 11. (canceled)
 12. A bifunctional compound, which is represented by any one of structures 1-6:

or a pharmaceutically acceptable salt or stereoisomer thereof.
 13. A pharmaceutical composition, comprising a therapeutically effective amount of the bifunctional compound or a pharmaceutically acceptable salt or stereoisomer thereof of claim 1, and a pharmaceutically acceptable carrier.
 14. A method of treating a disease or disorder mediated by IRAK 1, IRAK 4 or IRAK 1 and IRAK4, comprising administering a therapeutically effective amount of the bifunctional compound or pharmaceutically acceptable salt or stereoisomer thereof of claim
 1. 15. The method of claim 14, wherein the disease is cancer.
 16. The method of claim 15, wherein the cancer is a B-cell cancer or neuroblastoma.
 17. The method of claim 16, wherein said B-cell cancer is selected from the group consisting of Waldenstrom's macroglobulinemia (WM), activated B-cell (ABC) subtype of diffuse large B-cell lymphoma (DLBCL), primary central nervous system (CNS) lymphoma (PCNSL), marginal zone lymphoma (MZL), and chronic lymphocytic leukemia (CLL).
 18. The method of claim 16, further comprising co-administering an inhibitor of Bruton's tyrosine kinase (BTK).
 19. The method of claim 18, wherein the BTK inhibitor is ibrutinib.
 20. (canceled)
 21. A pharmaceutical composition, comprising a therapeutically effective amount of the bifunctional compound or a pharmaceutically acceptable salt or stereoisomer of claim 12, and a pharmaceutically acceptable carrier.
 22. The compound of claim 12, which is represented by structure 1:

or a pharmaceutically acceptable salt or stereoisomer thereof.
 23. The compound of claim 12, which is represented by structure 2:

or a pharmaceutically acceptable salt or stereoisomer thereof.
 24. The compound of claim 12, which is represented by structure 3:

or a pharmaceutically acceptable salt or stereoisomer thereof.
 25. The compound of claim 12, which is represented by structure 4:

or a pharmaceutically acceptable salt or stereoisomer thereof. 